UWORLD - CHEM

Which of the following pressure measurements is equivalent to a pressure of 152 mmHg? 0.2 atm 20.3 kPa 76 torr A.I and II only B.I and III only C.II and III only D.I, II, and III

A These units can be converted from one to another by using appropriate conversion factors, given that 1 atm = 760 mmHg = 760 torr = 101,325 Pa = 101.325 kPa.

Chemical behavior is governed largely by the number of ______ in an atom's valence shell. Atoms with the same number of _______ electrons (same column of the periodic table) have similar chemical properties.

Chemical behavior is governed largely by the number of electrons in an atom's valence shell. Atoms with the same number of valence electrons (same column of the periodic table) have similar chemical properties.

Electrons within an atom can exist only in particular, discrete ____ levels that are identified by _____numbers (such as the principle _____ number n)

Electrons within an atom can exist only in particular, discrete energy levels that are identified by quantum numbers (such as the principle quantum number n)

Elements with a ______ first ionization energy are easier to ionize in reactions than elements with a ______ ionization energy.

Elements with a lower first ionization energy are easier to ionize in reactions than elements with a higher ionization energy.

_______ of a positron and _______ capture both result in a decrease in the atomic number

Emission of a positron and electron capture both result in a decrease in the atomic number,

When comparing atoms across the same row of the periodic table, which of the groups will contain the atom with the lowest second ionization energy?

Group 2

If a reaction is irreversible, it means it is under _______ control

If a reaction is irreversible, it means it is under kinetic control

Impurities that undergo the same oxidation-reduction behavior as the _____ cannot be distinguished from the analyte and ______ the accuracy of the measured equivalence point in a redox titration.

Impurities that undergo the same oxidation-reduction behavior as the analyte cannot be distinguished from the analyte and decrease the accuracy of the measured equivalence point in a redox titration.

In chelate formation reactions, a metal cation and a _____react to form one or more rings via a pincer-like _______ bonding arrangement.

In chelate formation reactions, a metal cation and a ligand react to form one or more rings via a pincer-like coordinate bonding arrangement.

In the Bohr model of the atom, electrons move around the nucleus in ______circular orbits at particular intervals. Electrons in orbits farther from the nucleus have _______energy. Energy equal to the difference between two orbits is _____ by an electron moving to a higher orbit and is _______ by an electron moving to a lower orbit.

In the Bohr model of the atom, electrons move around the nucleus in fixed circular orbits at particular intervals. Electrons in orbits farther from the nucleus have higher energy. Energy equal to the difference between two orbits is absorbed by an electron moving to a higher orbit and is emitted by an electron moving to a lower orbit.

Ionic radii _________ in size across a period and _________down a group on the periodic table. The use of isoelectronic series is helpful in comparing cations, anions, and neutral atoms.

Ionic radii decrease in size across a period and increase down a group on the periodic table. The use of isoelectronic series is helpful in comparing cations, anions, and neutral atoms.

Sublimation can occur only at pressures below the ________ point

Sublimation can occur only at pressures below the triple point

What is the activation Energy and how does a catalyst affect it?

The activation energy of a reaction is the difference in energy between the reactants and the transition state of a reaction. Catalysts lower the activation energy by stabilizing the high-energy transition state.

The equivalence point occurs when the amounts of acid and base in a solution are the _______. The equivalence point on a titration curve occurs in the ______ of the steepest part of the curve.

The equivalence point occurs when the amounts of acid and base in a solution are the same. The equivalence point on a titration curve occurs in the middle of the steepest part of the curve.

The solubility of a compound is indicated by the solubility product constant Ksp, and the Ksp values of two compounds can inform which compound to selectively ______ during the separation of a compound mixture using the _______ ________ effect.

The solubility of a compound is indicated by the solubility product constant Ksp, and the Ksp values of two compounds can inform which compound to selectively precipitate during the separation of a compound mixture using the common ion effect.

Why does , EA generally decreases (becomes more positive) going down a group ?

because the electron is added at an increased distance from the nucleus.

Which compound has the bond with the smallest dipole moment? A.H2O B.H2S C.H2Se D.H2Te

electronegativity increases when moving up a column on the periodic table. As a result, the electronegativity difference (and dipole moment) of the hydrogen-chalcogen bond increases moving up the column. Therefore, the ranking of the dipole moments for each of the four bonds (from largest to smallest) is as follows: H−O > H−S > H−Se > H−Te. ANS: D

What are the relationship between Torr, HHmg, and Pa, and KPa?

1 atm=760 mmHg=760 torr=101,325 Pa=101.325 kPa

During the synthesis of a tosylate, which of the following pairs of atoms form a covalent bond? A.C and Cl B.S and O C.S and Cl D.C and O

A C-O bond and and a S-Cl are broken; an a S-O bond is formed ANS: B

A catalyst is a chemical species that is added to a reaction to ______ the rate of the reaction by stabilizing the transition state and _______ the activation energy of the reaction. A catalyst does not change the amount of _______ produced and does not change the relative _______of the reactants and products.

A catalyst is a chemical species that is added to a reaction to increase the rate of the reaction by stabilizing the transition state and decreasing the activation energy of the reaction. A catalyst does not change the amount of products produced and does not change the relative energies of the reactants and products.

A concentration cell is a type of _______ cell in which ions diffuse across a membrane, creating a _________. Because ________ is the driving force behind electron transfer, the standard potential of a concentration cell is positive whereas the concentration is different between the two compartments of the cell until it reaches equilibrium.

A concentration cell is a type of galvanic cell in which ions diffuse across a membrane, creating a potential. Because concentration is the driving force behind electron transfer, the standard potential of a concentration cell is positive whereas the concentration is different between the two compartments of the cell until it reaches equilibrium.

A _______ bond is formed by shared valence electrons between two atoms (usually two nonmetals). However, differences in ________ can result in unequal electron sharing. In such an arrangement, a polar covalent bond results, wherein the electrons in the bond are pulled closer to the atom of ______ electronegativity (giving it a partial negative charge) and away from the atom of lesser electronegativity (giving it a partial positive charge). This separation of charges across the bond results in a vector quantity called a ______ moment. Therefore, the magnitude of the dipole moment _________ as the difference in electronegativity between the two atoms in the bond increases.

A covalent bond is formed by shared valence electrons between two atoms (usually two nonmetals). However, differences in electronegativity can result in unequal electron sharing. In such an arrangement, a polar covalent bond results, wherein the electrons in the bond are pulled closer to the atom of greater electronegativity (giving it a partial negative charge) and away from the atom of lesser electronegativity (giving it a partial positive charge). This separation of charges across the bond results in a vector quantity called a dipole moment. Therefore, the magnitude of the dipole moment increases as the difference in electronegativity between the two atoms in the bond increases.

A fuel cell is a type of _______ cell whose reactants are continuously supplied at the anode and cathode, and whose products are continuously removed from the system. Although outside material is continuously supplied to the fuel cell, its reaction is still spontaneous, meaning that the Eocell is positive.

A fuel cell is a type of galvanic cell whose reactants are continuously supplied at the anode and cathode, and whose products are continuously removed from the system. Although outside material is continuously supplied to the fuel cell, its reaction is still spontaneous, meaning that the Eocell is positive.

What does the "A" in Arrhenius equation show?

A is a constant that represents the collision frequency and structural factors specific to the reactants. The exponential term e−EaRT corresponds to the fraction of collisions with enough kinetic energy to overcome the activation energy Ea at a given temperature T.

A reference electrode contains a known _____potential and ______of ions. When both electrodes in a cell contain the ______ chemical species (a concentration cell), the electric potential difference (voltage) between the electrodes depends only on the relative _______of these species.

A reference electrode contains a known electric potential and concentration of ions. When both electrodes in a cell contain the same chemical species (a concentration cell), the electric potential difference (voltage) between the electrodes depends only on the relative concentrations of these species.

In the ultraviolet (UV) range, pyrimidine has maximum absorptions at 240 nm and 280 nm, and the absorption at 280 nm is due to nonbonding electron excitation. The nonbonding electrons on nitrogen in pyrimidine undergo which of the following transitions when absorbing UV light? A.π → π* B. n → π* C.π* → π D.π* → n

ANS: B

What are the oxidizing and reducing agents, respectively, in the reaction below? 2HCl + H2 O2 + MnO 2→ O2 + MnCl2 + 2H2O A) H2O2; HCl B) H2O2; MnO2 C) MnO2; HCl D) MnO2; H2O2

ANS: D AAMC 10 . Q. 24

Adding ligands that can form soluble _______ complexes with metal ions in a solution can _______ the solubility of ionic salts. This occurs by applying Le Châtelier's principle to disrupt the solubility equilibrium and shift the reaction toward the products.

Adding ligands that can form soluble coordination complexes with metal ions in a solution can enhance the solubility of ionic salts. This occurs by applying Le Châtelier's principle to disrupt the solubility equilibrium and shift the reaction toward the products.

Alkali metals occupy Group 1 and have the _______ first ionization energies of all the element groups. As the atoms in the alkali metal group ______ in size moving down the column, the valence electron occupies an increasingly ______ energy level, and therefore is ______ tightly bound. As a result, ______energy is required to remove the electron from the valence shell of larger alkali metals, which makes them _______ reactive toward an ionizing reaction. As the smallest atom in the group with a valence electron in a lower energy level, lithium is the _____ reactive of the alkali metals

Alkali metals occupy Group 1 and have the lowest first ionization energies of all the element groups. As the atoms in the alkali metal group increase in size moving down the column, the valence electron occupies an increasingly higher energy level, and therefore is less tightly bound. As a result, less energy is required to remove the electron from the valence shell of larger alkali metals, which makes them more reactive toward an ionizing reaction. As the smallest atom in the group with a valence electron in a lower energy level, lithium is the least reactive of the alkali metals

Alkali metals, or Group 1 metals, are known to be very reactive because of their ______ first ionization energy, _____ atomic radius, and _______ electronegativity. The alkali metals have one electron in their valence shell, which they readily donate to form strong ionic bonds with nonmetals such as the halogens (Group 7A, or Group 17). As the atoms in the alkali metal group _______ in size, the valence electrons occupy higher energy levels, and ______ energy is required to remove an electron from the valence shell. Therefore, ______ alkali metals are more reactive.

Alkali metals, or Group 1 metals, are known to be very reactive because of their low first ionization energy, large atomic radius, and small electronegativity. The alkali metals have one electron in their valence shell, which they readily donate to form strong ionic bonds with nonmetals such as the halogens (Group 7A, or Group 17). As the atoms in the alkali metal group increase in size, the valence electrons occupy higher energy levels, and less energy is required to remove an electron from the valence shell. Therefore, larger alkali metals are more reactive.

Although a catalyst stabilizes the high-energy ______ state of a reaction, the extent to which a catalyst stabilizes the transition state does not affect the ______ evolved from the reaction.

Although a catalyst stabilizes the high-energy transition state of a reaction, the extent to which a catalyst stabilizes the transition state does not affect the heat evolved from the reaction.

Although individual pi bonds are ______ than sigma bonds, a double bond is composed of both a sigma and a pi bond, and therefore is stronger than a single bond

Although individual pi bonds are weaker than sigma bonds, a double bond is composed of both a sigma and a pi bond, and therefore is stronger than a single bond

Although the electromotive force for a nonspontaneous reaction in an electrolytic cell is _______, the applied potential must be _______ to overcome the negative potential of the reverse reaction.

Although the electromotive force for a nonspontaneous reaction in an electrolytic cell is negative, the applied potential must be positive to overcome the negative potential of the reverse reaction.

An aldehyde and a _______ amine react to form an enamine via an acid-catalyzed addition of the amine followed by an acid-catalyzed dehydration.

An aldehyde and a secondary amine react to form an enamine via an acid-catalyzed addition of the amine followed by an acid-catalyzed dehydration.

An imine is an analogue of ketones and aldehydes that contains a carbon-nitrogen double bond. Imines are formed from a ketone or aldehyde and ______ or a ______ amine via an acid-catalyzed addition of the amine followed by an acid-catalyzed __________.

An imine is an analogue of ketones and aldehydes that contains a carbon-nitrogen double bond. Imines are formed from a ketone or aldehyde and NH3 or a primary amine via an acid-catalyzed addition of the amine followed by an acid-catalyzed dehydration.

An increased oxidation state corresponds to a _____ of electrons (oxidation), whereas a decreased oxidation state results from _____ electrons (reduction). A change of one unit occurs for each electron transferred

An increased oxidation state corresponds to a loss of electrons (oxidation), whereas a decreased oxidation state results from gaining electrons (reduction). A change of one unit occurs for each electron transferred

Anions in an isoelectronic series are generally ______than neutral atoms and cations in the series.

Anions in an isoelectronic series are generally larger than neutral atoms and cations in the series.

As the atoms in the alkaline-earth metal group increase in size moving down the column, the valence electrons occupy an increasingly ______ energy level and therefore are ______ bound. Accordingly, ____ energy is required to remove the electrons from the valence shell of larger alkaline-earth metals. Consequently, the reactivity of the alkaline-earth metals ________ with increasing atomic number

As the atoms in the alkaline-earth metal group increase in size moving down the column, the valence electrons occupy an increasingly higher energy level and therefore are less tightly bound. Accordingly, less energy is required to remove the electrons from the valence shell of larger alkaline-earth metals. Consequently, the reactivity of the alkaline-earth metals increases with increasing atomic number

As the pressure increases, the gas particles are forced to get closer and closer to each other until the distance between different particles is _______ than the radius of the particles. As such, we can no longer assume that the gas particles have negligible ______. In addition, at high pressures, particles cannot move as freely, and the interactions (__________ forces) between them become significant.

As the pressure increases, the gas particles are forced to get closer and closer to each other until the distance between different particles is smaller than the radius of the particles. As such, we can no longer assume that the gas particles have negligible volumes. In addition, at high pressures, particles cannot move as freely, and the interactions (intermolecular forces) between them become significant.

Because vacuum distillations are performed under _______ pressure, the boiling point of a compound under vacuum will ______ relative to its boiling point at atmospheric pressure. Therefore, the simple distillation boiling point of a molecule is ______ than the boiling point of that molecule under vacuum (ie, simple distillation bp > vacuum distillation bp).

Because vacuum distillations are performed under reduced pressure, the boiling point of a compound under vacuum will decrease relative to its boiling point at atmospheric pressure. Therefore, the simple distillation boiling point of a molecule is greater than the boiling point of that molecule under vacuum (ie, simple distillation bp > vacuum distillation bp).

Both alkali metals and alkaline-earth metals (except _____) form ________ in water while releasing ________ in the process, the alkaline-earth metals are in Group 2

Both alkali metals and alkaline-earth metals (except beryllium) form basic hydroxides in water while releasing hydrogen gas, the alkaline-earth metals are in Group 2

Carbon atoms in sugars are numbered beginning with the carbon that is closest to the anomeric carbon when the sugar is in linear form. For aldoses such as glucose, the anomeric carbon is ______, whereas for ketoses such as fructose, the anomeric carbon is _______. α-D-fructose and β-D-fructose are diastereomers that differ in orientation at _______ (the anomeric carbon) only. Therefore, α-D-fructose and β-D-fructose are _______.

Carbon atoms in sugars are numbered beginning with the carbon that is closest to the anomeric carbon when the sugar is in linear form. For aldoses such as glucose, the anomeric carbon is C1, whereas for ketoses such as fructose, the anomeric carbon is C2. α-D-fructose and β-D-fructose are diastereomers that differ in orientation at C2 (the anomeric carbon) only. Therefore, α-D-fructose and β-D-fructose are anomers.

Catabolism breaks down biological fuel molecules such as carbohydrates, lipids, and proteins, releasing ______ as they are ______. Oxidation cannot occur without reduction, so some other molecule must be ________ in the process.

Catabolism breaks down biological fuel molecules such as carbohydrates, lipids, and proteins, releasing energy as they are oxidized. Oxidation cannot occur without reduction, so some other molecule must be reduced in the process.

Charging a battery involves forcing the oxidation-reduction reaction to run in a _______ direction by applying an _______voltage. Any circuit has some amount of internal resistance that will deplete a portion of the applied voltage. Therefore, a _______ voltage than that produced by discharging the battery is required to recharge it.

Charging a battery involves forcing the oxidation-reduction reaction to run in a nonspontaneous direction by applying an external voltage. Any circuit has some amount of internal resistance that will deplete a portion of the applied voltage. Therefore, a higher voltage than that produced by discharging the battery is required to recharge it.

Compounds that react with bases and produce solutions with pH < 7 can be classified as _____, whereas compounds that react with ______ and form solutions with pH > 7 can be classified as basic.

Compounds that react with bases and produce solutions with pH < 7 can be classified as acidic, whereas compounds that react with acids and form solutions with pH > 7 can be classified as basic.

Compounds with dsp3 hybridization and no lone pairs are ________ _______. If a compound with dsp3 hybridization has either one or two lone pairs, it will have a _______ or ________ geometry, respectively.

Compounds with dsp3 hybridization and no lone pairs are trigonal bipyramidal. If a compound with dsp3 hybridization has either one or two lone pairs, it will have a see-saw or T-shaped geometry, respectively.

Compounds with ________ (no lone pairs) and _________ (two lone pairs) molecular geometries have six electron-dense areas around a d2sp3 hybridized central atom.

Compounds with octahedral (no lone pairs) and square planar (two lone pairs) molecular geometries have six electron-dense areas around a d2sp3 hybridized central atom.

Coordinate covalent bonds are a special type of bond between a central atom, such as a metal, and a _________ . Both electrons in the bond come from the ______. Coordination bonds are neither covalent nor ionic but have some properties of both bond types. The metal ion maintains its oxidation state, as in the case of an ______ bond, and the ligands are not charged but are usually electronegative, as in ________ bonds. The metal and its ligands together form a complex, and the number of ________ bonds to the metal is known as the coordination number.

Coordinate covalent bonds are a special type of bond between a central atom, such as a metal, and a ligand. Both electrons in the bond come from the ligand. Coordination bonds are neither covalent nor ionic but have some properties of both bond types. The metal ion maintains its oxidation state, as in the case of an ionic bond, and the ligands are not charged but are usually electronegative, as in covalent bonds. The metal and its ligands together form a complex, and the number of coordinate bonds to the metal is known as the coordination number.

Coordinate covalent bonds, unlike covalent bonds, are formed between two atoms when both of the shared electrons are donated by the same atom. Such coordinate bonds are often formed between electron-________ metal ions and molecules called ______ that contain one or more electron-rich atoms with available lone-pair electrons. The coordinately bonded metal and its ligands are called a __________.

Coordinate covalent bonds, unlike covalent bonds, are formed between two atoms when both of the shared electrons are donated by the same atom. Such coordinate bonds are often formed between electron-poor metal ions and molecules called ligands that contain one or more electron-rich atoms with available lone-pair electrons. The coordinately bonded metal and its ligands are called a complex.

Deviations from "ideal" occur at very _____ pressures and ______ temperatures.

Deviations from "ideal" occur at very high pressures and low temperatures.

Due to differences in the efficiency and mode of the orbital overlap, σ and π bond dissociation energies are not equivalent or proportional, and ______ bonds require more energy than ______bonds to be broken.

Due to differences in the efficiency and mode of the orbital overlap, σ and π bond dissociation energies are not equivalent or proportional, and σ bonds require more energy than π bonds to be broken.

During electrolysis, electron-rich species (such as anions) are _______ at the electron-deficient anode. in the electrolysis of molten NaCl, Cl− is oxidized to Cl2 gas . electron-deficient species (such as _______) are ________ at the electron-rich cathode. In the electrolysis of molten NaCl, Na+ is reduced to Na metal

During electrolysis, electron-rich species (such as anions) are oxidized at the electron-deficient anode. in the electrolysis of molten NaCl, Cl− is oxidized to Cl2 gas . electron-deficient species (such as metal cations) are reduced at the electron-rich cathode. In the electrolysis of molten NaCl, Na+ is reduced to Na metal

During _____ capture, a nuclear proton captures an inner electron near the nucleus and then converts to a_________. This decreases the atomic number by 1 but leaves the mass number the same.

During electron capture, a nuclear proton captures an inner electron near the nucleus and then converts to a neutron. This decreases the atomic number by 1 but leaves the mass number the same.

During ventilation, _____ is expelled from the lungs. An increase in ventilation (hyperventilation) _____levels of CO2 in the blood. Removal of CO2 then shifts the reaction to the left to maintain equilibrium. This shift results in a decrease in _______ levels, which translates to a _____ in HCO3− and H+ (increase in pH) in pulmonary circulation. Clinically, this is referred to as respiratory _______

During ventilation, CO2 is expelled from the lungs. An increase in ventilation (hyperventilation) decreases levels of CO2 in the blood. Removal of CO2 then shifts the reaction to the left to maintain equilibrium. This shift results in a decrease in carbonic acid levels, which translates to a decrease in HCO3− and H+ (increase in pH) in pulmonary circulation. Clinically, this is referred to as respiratory alkalosis

The effective nuclear charge experienced by the valence electrons of a neutral nitrogen atom is: A.+7 B.+5 C.−3 D.−5.

Each proton in the nucleus of an atom contributes one unit of positive charge that exerts an electrostatic attraction on the negatively charged electrons around the atom. However, in atoms with several electrons, the core electrons positioned between the valence electrons and the nucleus provide a shielding constant S that counteracts part of the full nuclear charge Z attracting the valence electrons. As a result, the valence electrons experience an effective nuclear charge Zeff that is less than the full nuclear charge, such that Zeff=Z−S Precisely calculating S is difficult and depends on the electron density of a given electron orbital configuration, but a rough, first-order approximation can be made by assuming that S is approximately equal to the number of core electrons. When comparing atoms within the same period (row) of the periodic table, this approximation shows that Zeff increases as the atomic number increases. However, because this approximation does not account for electron density or orbital distance, it is less useful for precisely comparing Zeff between atoms in the same group (column) or in different rows of the periodic table. Applying this approximation to calculate the Zeff experienced by the valence electrons of a nitrogen atom with 7 protons (Z = 7) and 2 core electrons (S = 2) gives: Zeff,N=Z−S=(7−2)=+5

Electrochemical cells harness energy from an oxidation-reduction reaction by separating the reaction into half-cells. At the anode, one reactant is oxidized (____ electrons); at the cathode, another reactant is reduced (_______ electrons). A wire connects the two half-cells and allows for the flow of ______ from the anode to the cathode. This produces a _____ that can be used to do ________

Electrochemical cells such as E3 harness energy from an oxidation-reduction reaction by separating the reaction into half-cells. At the anode, one reactant is oxidized (loses electrons); at the cathode, another reactant is reduced (gains electrons). A wire connects the two half-cells and allows for the flow of electrons from the anode to the cathode. This produces a current that can be used to do work.

Electron affinity is defined as the change in energy resulting from adding an _______ to a neutral atom of an element X in the _____ state to form an ______ with a −1 charge: X(g) + e− → X−(g)

Electron affinity is defined as the change in energy resulting from adding an electron to a neutral atom of an element X in the gas state to form an anion with a −1 charge: X(g) + e− → X−(g)

Electron affinity is defined as the change in energy resulting from adding an_____ to a neutral atom of an element X in the ______ state to form an anion with a −1 charge: X(g) + e− → X−(g) When a stable anion is formed, ______ is released, which results in a ______ value for the change in energy. Therefore, elements with a more ______electron affinity _____ readily accept the addition of an electron.

Electron affinity is defined as the change in energy resulting from adding an electron to a neutral atom of an element X in the gas state to form an anion with a −1 charge: X(g) + e− → X−(g) When a stable anion is formed, energy is released, which results in a negative value for the change in energy. Therefore, elements with a more negative electron affinity more readily accept the addition of an electron.

_______ ________ is the measure of energy change when an electron is added to an atom in the gaseous state. Electron-electron repulsions result in a ________ electron affinity.

Electron affinity is the measure of energy change when an electron is added to an atom in the gaseous state. Electron-electron repulsions result in a decreased electron affinity.

Electron affinity trends show that apart from some exceptions caused by atomic size and orbital-filling effects, values tend to become ______negative (higher affinity) moving left to right across a period and become _______ positive (lower affinity) moving down a group on the periodic table.

Electron affinity trends show that apart from some exceptions caused by atomic size and orbital-filling effects, values tend to become more negative (higher affinity) moving left to right across a period and become more positive (lower affinity) moving down a group on the periodic table.

Elements with loosely bound valence electrons have ______ first ionization energies (i.e., are easier to ionize) than elements with tightly bound valence electrons. On the periodic table, the first ionization energy tends to ______ with increasing atomic number moving across a period (row), but it tends to ______ moving down a group (column) with some intermittent exceptions

Elements with loosely bound valence electrons have lower first ionization energies (i.e., are easier to ionize) than elements with tightly bound valence electrons. On the periodic table, the first ionization energy tends to increase with increasing atomic number moving across a period (row), but it tends to decrease moving down a group (column) with some intermittent exceptions

Energy density relates the E°cell of a battery to its ______, in which a battery with a high energy density has a _______ energy output, a ______ weight, or both.

Energy density relates the E°cell of a battery to its mass, in which a battery with a high energy density has a high energy output, a low weight, or both.

Fluorine is the most electronegative halogen and has the ______ atomic radius of the halogens. Therefore, H−F forms the ________, strongest bond of all the hydrogen halides. A short, strong H−X bond that is difficult to ionize in aqueous solution indicates a ______ acid

Fluorine is the most electronegative halogen and has the smallest atomic radius of the halogens. Therefore, H−F forms the shortest, strongest bond of all the hydrogen halides. A short, strong H−X bond that is difficult to ionize in aqueous solution indicates a weak acid

Which of the following statement(s) is(are)consistent with the molar mass of ammonium carbonate? 1) 1.00 mol of (NH4)2CO3 contains 96.11 g of mass. 2) 96.11 g of (NH4)2CO3 contains 6.022 × 1023 (NH4)2CO3 molecules. 3) 96.11 amu of (NH4)2CO3 contains 1.00 mol (NH4)2CO3.

For (NH4)2CO3, a molecular weight of 96.11 amu means that 1.00 mole of (NH4)2CO3 molecules has a mass of 96.11 g (Number I). Likewise, a 96.11 g sample of (NH4)2CO3 will contain 1 mole (6.022 × 1023 units) of (NH4)2CO3 molecules (Number II). Conversely, 96.11 amu of (NH4)2CO3 refers only to a single molecule of (NH4)2CO3, which does not contain the same mass as a mole of (NH4)2CO3 molecules (Number III).

Galvanic cells are electrochemical cells that produce an ________ _______ as a result of the spontaneous transfer of electrons from the anode to the cathode. In any electrochemical cell, oxidation occurs at the ______ and reduction occurs at the ________

Galvanic cells are electrochemical cells that produce an electric potential as a result of the spontaneous transfer of electrons from the anode to the cathode. In any electrochemical cell, oxidation occurs at the anode and reduction occurs at the cathode.

Hybrid orbitals form when two or more atomic orbitals (s, p, d, f) combine into new orbitals of different shape and spatial orientation. An atom's hybridization and electron geometry are dictated by the number of hybrid orbitals (electron-dense areas) formed around the atom. As the number of electron-dense areas increases, _______ between orbitals increases. Electrons distribute themselves into specific configurations that minimize this repulsion. These electron distributions act as frames in which bonding may occur. The molecular geometry of a compound is determined only by the ________ of the bonds around the central atom, and nonbonding electron pairs are ignored. Two compounds may have the same number of electron-dense areas but different molecular geometries if they differ in number of lone electron pairs.

Hybrid orbitals form when two or more atomic orbitals (s, p, d, f) combine into new orbitals of different shape and spatial orientation. An atom's hybridization and electron geometry are dictated by the number of hybrid orbitals (electron-dense areas) formed around the atom. As the number of electron-dense areas increases, repulsion between orbitals increases. Electrons distribute themselves into specific configurations that minimize this repulsion. These electron distributions act as frames in which bonding may occur. The molecular geometry of a compound is determined only by the orientation of the bonds around the central atom, and nonbonding electron pairs are ignored. Two compounds may have the same number of electron-dense areas but different molecular geometries if they differ in number of lone electron pairs.

Hypoventilation (decreased gas exchange) leads to an _______ in CO2 levels in the blood. This shifts equilibrium to the right, resulting in ______ levels of H2CO3, HCO3− and H+ (a decrease in pH). Clinically, this is referred to as respiratory _________

Hypoventilation (decreased gas exchange) leads to an increase in CO2 levels in the blood. This shifts equilibrium to the right, resulting in increased levels of H2CO3, HCO3− and H+ (a decrease in pH). Clinically, this is referred to as respiratory acidosis.

In UV spectroscopy, a compound in solution is irradiated with UV light; the amount of UV light absorbed by the compound is measured at each wavelength and a spectrum is generated by plotting absorbance as a function of ______. Absorption of UV light causes an electron transition, or excitation, from the _______ state to a _______ energy level. In the ground state, π electrons from double bonds are in the π ______ molecular orbital, and nonbonding electrons are in the n nonbonding molecular orbital. Upon interactions with UV light of sufficient energy, these electrons are excited to the Lowest Unoccupied Molecular Orbital (LUMO), called the π* __________ orbital.

In UV spectroscopy, a compound in solution is irradiated with UV light; the amount of UV light absorbed by the compound is measured at each wavelength and a spectrum is generated by plotting absorbance as a function of wavelength. Absorption of UV light causes an electron transition, or excitation, from the ground state to a higher energy level. In the ground state, π electrons from double bonds are in the π bonding molecular orbital, and nonbonding electrons are in the n nonbonding molecular orbital. Upon interactions with UV light of sufficient energy, these electrons are excited to the Lowest Unoccupied Molecular Orbital (LUMO), called the π* antibonding orbital.

In all forms of beta decay, the mass number remains ______ whereas the atomic number ________ (β− decay) or _________ (β+ decay and electron capture) by 1. β− decay converts a _______ into a _________and emits an electron. β+ decay and electron capture convert a ______ into a ________ (the opposite of a β− decay).

In all forms of beta decay, the mass number remains unchanged whereas the atomic number increases (β− decay) or decreases (β+ decay and electron capture) by 1. β− decay converts a neutron into a proton and emits an electron. β+ decay and electron capture convert a proton into a neutron (the opposite of a β− decay).

In all three forms of beta decay, the ______ number remains unchanged whereas the atomic number either ______ (β−-decay) or _______(β+-decay and electron capture) by 1. As the atomic number changes, the ______ of the element changes accordingly

In all three forms of beta decay, the mass number remains unchanged whereas the atomic number either increases (β−-decay) or decreases (β+-decay and electron capture) by 1. As the atomic number changes, the identity of the element changes accordingly

In an SN2 reaction, an electrophile that has an Rconfiguration before substitution will adopt an Sconfiguration after the reaction and vice versa, if the ________ has the same priority ranking as the leaving group.

In an SN2 reaction, an electrophile that has an Rconfiguration before substitution will adopt an Sconfiguration after the reaction and vice versa, if the nucleophile has the same priority ranking as the leaving group.

In an electrolytic cell, electric current from an external source is supplied to provide the necessary ______ to perform a nonspontaneous (________), electrochemical _________ (electrolysis) of a compound. The charge used during electrolysis can be measured in a unit called the faraday, where 1 faraday equals the _________present in 1 mole of _________.

In an electrolytic cell, electric current from an external source is supplied to provide the necessary energy to perform a nonspontaneous (endergonic), electrochemical decomposition (electrolysis) of a compound. The charge used during electrolysis can be measured in a unit called the faraday, where 1 faraday equals the electric charge present in 1 mole of electrons.

In contrast to the thermodynamics of a reaction, which indicate whether a reaction will be _____ or not, the kinetics of a reaction describe how ______ a reaction will take to reach completion under given conditions. A reaction may be spontaneous, but it may also proceed so ______ that it does not reach completion in a reasonable amount of time. A catalyst increases the _____ (kinetics) of the reaction by ______ the activation energy required for the reaction to progress at a given temperature. However, a catalyst does not affect the ______ of products produced or the ________ (thermodynamics) of the reaction.

In contrast to the thermodynamics of a reaction, which indicate whether a reaction will be spontaneous or not, the kinetics of a reaction describe how long a reaction will take to reach completion under given conditions. A reaction may be spontaneous, but it may also proceed so slowly that it does not reach completion in a reasonable amount of time. A catalyst increases the rate (kinetics) of the reaction by decreasing the activation energy required for the reaction to progress at a given temperature. However, a catalyst does not affect the amount of products produced or the enthalpy (thermodynamics) of the reaction.

In general, a C-O single bond has a _____ bond dissociation energy than a C=O double bond, and a C=O double bond has a ______ bond dissociation energy than a C≡O triple bond.

In general, a C-O single bond has a lower bond dissociation energy than a C=O double bond, and a C=O double bond has a lower bond dissociation energy than a C≡O triple bond.

In hemoglobin, the metal ion Fe2+ is positively charged whereas the ________ atoms (nitrogen) are neutral, resulting in a net charge of +2 for the complex. Unlike ______ bonds, the donor atoms do not give electrons to the positively charged metal. Instead ________ often surround the complex in solution to balance the metal's positive charge

In hemoglobin, the metal ion Fe2+ is positively charged whereas the donor atoms (nitrogen) are neutral, resulting in a net charge of +2 for the complex. Unlike ionic bonds, the donor atoms do not give electrons to the positively charged metal. Instead counterions often surround the complex in solution to balance the metal's positive charge

In solutions containing two salts that have an ion in common, the common ion supplied by the one salt produces a common ion effect that shifts the equilibrium of the other salt to the left and _______ its solubility.

In solutions containing two salts that have an ion in common, the common ion supplied by the one salt produces a common ion effect that shifts the equilibrium of the other salt to the left and decreases its solubility.

Ionic radii tend to _______ in size across a period (row) of the periodic table (left to right) and _______ moving down a group (column). This trend occurs for metal cations, and then resets and repeats for anions beginning near the division between metals and nonmetals, past which anions tend to preferentially form. Losing electrons to form a cation causes the remaining electrons to experience a _______ effective nuclear charge (Zeff), pulling the electrons closer to the nucleus. Conversely, gaining electrons to form an anion produces _______ electronic repulsion and nuclear shielding (lesser Zeff), which pushes electrons farther from the nucleus

Ionic radii tend to decrease in size across a period (row) of the periodic table (left to right) and increase moving down a group (column). This trend occurs for metal cations, and then resets and repeats for anions beginning near the division between metals and nonmetals, past which anions tend to preferentially form. Losing electrons to form a cation causes the remaining electrons to experience a greater effective nuclear charge (Zeff), pulling the electrons closer to the nucleus. Conversely, gaining electrons to form an anion produces greater electronic repulsion and nuclear shielding (lesser Zeff), which pushes electrons farther from the nucleus

Ionization energy is the _______required to remove an electron from an atom. Because of the associated ionization and electron transfer involved in forming ______ bonds, the reactivity of atoms forming ionic compounds ______ as the ionization energy _______

Ionization energy is the energy required to remove an electron from an atom. Because of the associated ionization and electron transfer involved in forming ionic bonds, the reactivity of atoms forming ionic compounds increases as the ionization energy decreases.

Irreversible reactions tend to be under _______ control, which favors products whose pathways have the _________activation energy. Reversible reactions tend to be under ________ control, which favors the most stable product.

Irreversible reactions tend to be under kinetic control, which favors products whose pathways have the lowest activation energy. Reversible reactions tend to be under thermodynamic control, which favors the most stable product.

Isotopes are atoms of the same element that have the same number of _____ but a different number of ______ in the nucleus. Isotopes of the same element have nearly _____ chemical properties but differ in their _____ properties.

Isotopes are atoms of the same element that have the same number of protons but a different number of neutrons in the nucleus. Isotopes of the same element have nearly identical chemical properties but differ in their physical properties.

Does A catalyst does not change the inherent energy required to break the bonds?

NO

Nuclear _______ is the splitting of a large atomic nucleus into multiple smaller nuclei.

Nuclear fission is the splitting of a large atomic nucleus into multiple smaller nuclei.

Oxides are binary compounds consisting of oxygen bound with only one other element. They can be classified as acidic, basic, or neutral, depending on their reactions with water, acids, and bases. ______ oxides react with water to form acidic compounds that produce a solution pH < 7. Acidic oxides also react with bases to form _______. In contrast, basic oxides react with water to form ______ compounds that yield a solution pH > 7, and basic oxides form _____ by reacting with acids. Neutral oxides are unreactive toward water, acids, and bases.

Oxides are binary compounds consisting of oxygen bound with only one other element. They can be classified as acidic, basic, or neutral, depending on their reactions with water, acids, and bases. Acidic oxides react with water to form acidic compounds that produce a solution pH < 7. Acidic oxides also react with bases to form salts. In contrast, basic oxides react with water to form basic compounds that yield a solution pH > 7, and basic oxides form salts by reacting with acids. Neutral oxides are unreactive toward water, acids, and bases.

_______ is the extent to which an electron cloud of an atom can be distorted by an external charge or by an applied electric field to produce a dipole.

Polarizability is the extent to which an electron cloud of an atom can be distorted by an external charge or by an applied electric field to produce a dipole.

Positron emission occurs during ______-decay, in which a nuclear _______ converts to a _______. This causes the atomic number of the nucleus to decrease by ____ while the ______ number of the nucleus remains unchanged.

Positron emission occurs during β+-decay, in which a nuclear proton converts to a neutron. This causes the atomic number of the nucleus to decrease by 1 while the mass number of the nucleus remains unchanged.

Radioactive beta decay can occur in three forms: β−-decay (________emission), β+-decay (_____emission), and electron capture. In β−-decay, a _____ converts to a nuclear ______ and emits an______. In β+-decay, a nuclear _____ converts to a ______ (the opposite of β−-decay) and ejects a ______ (an electron with a positive charge). In electron capture, a proton captures an ______ near the nucleus and converts to a ______ without a positron or electron emission.

Radioactive beta decay can occur in three forms: β−-decay (electron emission), β+-decay (positron emission), and electron capture. In β−-decay, a neutron converts to a nuclear proton and emits an electron. In β+-decay, a nuclear proton converts to a neutron (the opposite of β−-decay) and ejects a positron (an electron with a positive charge). In electron capture, a proton captures an electron near the nucleus and converts to a neutron without a positron or electron emission.

Shells are indicated using the _________number n, which relates to the distance of an ________ from the nucleus. _________are labeled by type (s, p, d, f), which relates to the shapes of the orbitals that hold a maximum of 2, 6, 10, and 14 electrons, respectively.

Shells are indicated using the principal quantum number n, which relates to the distance of an orbital from the nucleus. Subshells are labeled by type (s, p, d, f), which relates to the shapes of the orbitals that hold a maximum of 2, 6, 10, and 14 electrons, respectively.

The C=S double bond in carbon disulfide (CS2) consists of a combination of one σ bond and one π bond. Compared to the bond dissociation energy (bond strength) of the π bond, the bond dissociation energy of the σ bond portion of the C=S bond is:

Sigma bonds are lower in energy, more stable, and have a greater dissociation energy than π bonds. Although individual π bonds are weaker than σ bonds, double and triple bonds are composed of both σ and π bonds and are therefore stronger overall than a single bond. ANS: greater

Simple distillation is used for compounds with boiling points less than _____ °C, and that are more than _____ °C apart from each other. Vacuum distillation is used for compounds that ________ at their boiling point (typically boiling points greater than 150 °C), causing the boiling point to decrease and thereby preventing degradation. Simple and vacuum distillations are set up in the same way, except that simple distillations are done at ______ pressure, whereas vacuum distillations are connected to a vacuum pump and performed at _____ pressure.

Simple distillation is used for compounds with boiling points less than 150 °C, and that are more than 25 °C apart from each other. Vacuum distillation is used for compounds that decompose at their boiling point (typically boiling points greater than 150 °C), causing the boiling point to decrease and thereby preventing degradation. Simple and vacuum distillations are set up in the same way, except that simple distillations are done at atmospheric pressure, whereas vacuum distillations are connected to a vacuum pump and performed at reduced pressure.

Some sugars can be classified as a special kind of diastereomer, known as an anomer, that differs in configuration at only the ______carbon. The α and β designations in a sugar's name refer to different orientations of the _______ group at the anomeric carbon.

Some sugars can be classified as a special kind of diastereomer, known as an anomer, that differs in configuration at only the anomeric carbon. The α and β designations in a sugar's name refer to different orientations of the hydroxyl group at the anomeric carbon.

The Arrhenius equation describes the relationship between the rate constant and the _______ and ________of a reaction. Both the rate constant and the rate of reaction decay exponentially with ________ activation energy and increase exponentially with ______temperature. Because catalysts ______the activation energy of a reaction, the rate constant is ______ for a catalyzed reaction than for an uncatalyzed reaction.

The Arrhenius equation describes the relationship between the rate constant and the temperature and activation energy of a reaction. Both the rate constant and the rate of reaction decay exponentially with increasing activation energy and increase exponentially with increasing temperature. Because catalysts lower the activation energy of a reaction, the rate constant is greater for a catalyzed reaction than for an uncatalyzed reaction.

The Strecker synthesis is used to make _____ amino acids from aldehydes using ______ and potassium cyanide (KCN). The first step of the reaction proceeds with protonation of the carbonyl oxygen by H3O+, followed by nucleophilic attack of the carbonyl carbon by ______, resulting in dehydration and imine formation. Therefore, an aldehyde and NH3 are used to form the _____ intermediate in the Strecker synthesis.

The Strecker synthesis is used to make α-amino acids from aldehydes using NH3 and potassium cyanide (KCN). The first step of the reaction proceeds with protonation of the carbonyl oxygen by H3O+, followed by nucleophilic attack of the carbonyl carbon by NH3, resulting in dehydration and imine formation. Therefore, an aldehyde and NH3 are used to form the imine intermediate in the Strecker synthesis.

The activation energy of a reaction is the difference in energy between the ________ (or ________) and the ______ state, illustrated as the maxima on the curve. A multistep reaction contains the same number of ________ as there are steps.

The activation energy of a reaction is the difference in energy between the reactants (or intermediates) and the transition state, illustrated as the maxima on the curve. A multistep reaction contains the same number of peaks as there are steps.

The amount of product formed in a reaction is dependent on the _______ _________ of the reaction. This constant is not changed by a _______, which only changes the rate at which equilibrium is achieved.

The amount of product formed in a reaction is dependent on the equilibrium constant of the reaction. This constant is not changed by a catalyst, which only changes the rate at which equilibrium is achieved.

The change in Gibbs free energy ΔG° for a reaction at a given temperature is related to the equilibrium constant Keq by the relationship ΔG° = −RT ln Keq. The values of pH and ΔG° are related by the acid dissociation constant _______, a special type of equilibrium constant.

The change in Gibbs free energy ΔG° for a reaction at a given temperature is related to the equilibrium constant Keq by the relationship ΔG° = −RT ln Keq. The values of pH and ΔG° are related by the acid dissociation constant Ka, a special type of equilibrium constant.

The chemical behavior of an atom is determined primarily by its ____ configuration, not by the number of _______ in the nucleus. As a result, isotopes of the same element have nearly identical chemical properties (such as _____ and ______) but differ in their physical properties (such as _________ and _________).

The chemical behavior of an atom is determined primarily by its electron configuration, not by the number of neutrons in the nucleus. As a result, isotopes of the same element have nearly identical chemical properties (such as bonding and reactivity) but differ in their physical properties (such as density and mass).

The common ion effect will cause the concentration of CuF2 to be ______ in 0.20 M NaF (common ion) than in pure water. The solubility cannot be the same in both solutions.

The common ion effect will cause the concentration of CuF2 to be lower in 0.20 M NaF than in pure water. The solubility cannot be the same in both solutions.

The ____ ________energy is the energy required to remove the first, most loosely bound valence electron (e−) from a neutral atom (X). It can be represented generally as follows: X + energy → X+ + e−

The first ionization energy is the energy required to remove the first, most loosely bound valence electron (e−) from a neutral atom (X). It can be represented generally as follows: X + energy → X+ + e−

The more ______ the electron affinity, the easier it is to add an _____ to the valence shell of an atom. In general, the electron affinity of nonmetals is more ______ than that of metals.

The more negative the electron affinity, the easier it is to add an electron to the valence shell of an atom. In general, the electron affinity of nonmetals is more negative than that of metals.

The nuclear charge Z influencing a valence electron is diminished by the shielding constant S, which results in an effective nuclear charge Zeff that is less than Z and increases as the atomic number increases. By assuming S is equal to the number of core electrons, Zeff can be estimated as: Zeff = Z - S.

The nuclear charge Z influencing a valence electron is diminished by the shielding constant S, which results in an effective nuclear charge Zeff that is less than Z and increases as the atomic number increases. By assuming S is equal to the number of core electrons, Zeff can be estimated as: Zeff = Z - S.

The overall energy of a bond is the sum of the energies of all _____ and ____ bonding contributors. When comparing single, double, and triple covalent bonds involving the same two types of atoms, the overall bond dissociation energy (the energy required to break the bond) tends to _______ (relative to a single bond) with each additional π bond. This is due in part to increased electron _____ between the atoms that participate in multiple bonds.

The overall energy of a bond is the sum of the energies of all σ and π bonding contributors. When comparing single, double, and triple covalent bonds involving the same two types of atoms, the overall bond dissociation energy (the energy required to break the bond) tends to increase (relative to a single bond) with each additional π bond. This is due in part to increased electron density between the atoms that participate in multiple bonds.

The same set of atoms can bond in different ways. For two chemical species to be the same, both the ______composition and the ______ bonding configuration must be the same.

The same set of atoms can bond in different ways. For two chemical species to be the same, both the elemental composition and the electronic bonding configuration must be the same.

The second ionization energy is the energy required to remove the _____ of two electrons from an atom. The second ionization energy tends to ______ across a period and to ______ down a group; however, ionizations involving core electrons are ______ energy than those involving valence electrons.

The second ionization energy is the energy required to remove the second of two electrons from an atom. The second ionization energy tends to increase across a period and to decrease down a group; however, ionizations involving core electrons are higher energy than those involving valence electrons.

The size of the halogen atom impacts the bond _____ and strength of hydrogen halide acids (H−X). Halogens are located in Group 7A (Group 17) on the right side of the periodic table and increase in size moving down the group. Therefore, halogens with a _____ atomic number have a ______ atomic radius and form ______, ______ H−X bonds that are more difficult to ionize. Smaller halogens are more electronegative and more readily attract electrons in the H−X bond toward itself, creating a _____ covalent bond.

The size of the halogen atom impacts the bond length and strength of hydrogen halide acids (H−X). Halogens are located in Group 7A (Group 17) on the right side of the periodic table and increase in size moving down the group. Therefore, halogens with a smaller atomic number have a smaller atomic radius and form shorter, stronger H−X bonds that are more difficult to ionize. Smaller halogens are more electronegative and more readily attract electrons in the H−X bond toward itself, creating a polar covalent bond.

The stability of the conjugate base of the hydrogen halides (X-) also affects _______. The conjugate base formed from a ______ halogen is less stable because it has a _______atomic radius (less surface area) and cannot spread out (stabilize) the negative charge as well as halogens with larger atomic radii (greater surface area).

The stability of the conjugate base of the hydrogen halides (X-) also affects acidity. The conjugate base formed from a smaller halogen is less stable because it has a smaller atomic radius (less surface area) and cannot spread out (stabilize) the negative charge as well as halogens with larger atomic radii (greater surface area).

The _________ dependence of solubility and the ________ _______ effect from relevant ions on the solubility equilibrium can be used to assist in selectively precipitating compounds during separations of mixtures.

The temperature dependence of solubility and the common ion effect from relevant ions on the solubility equilibrium can be used to assist in selectively precipitating compounds during separations of mixtures.

Thermodynamic values indicate if a reaction is ____ or not, but they do not indicate the _____ of a reaction. Enthalpy, entropy, and Gibbs free energy are ______functions, which mean they describe the ________differences between the reactants and the products in their current state. These values are _____ of the chemical pathway that a reaction takes to get from reactants to products.

Thermodynamic values indicate if a reaction is spontaneous or not, but they do not indicate the rate of a reaction. Enthalpy, entropy, and Gibbs free energy are state functions, which mean they describe the energetic differences between the reactants and the products in their current state. These values are independent of the chemical pathway that a reaction takes to get from reactants to products.

To find the overall reduction potential for a particular redox couple, subtract the standard reduction potential for the ________ agent (electron donor) from that of the ________ agent (electron acceptor)

To find the overall reduction potential for a particular redox couple, subtract the standard reduction potential for the reducing agent (electron donor) from that of the oxidizing agent (electron acceptor)

Ultraviolet (UV) light is electromagnetic radiation that corresponds to wavelengths between 200 nm and 400 nm, and UV absorption causes an electron transition from the ground state to a higher energy level. In the ground state, π electrons from double bonds are in the π ______ molecular orbital, and nonbonding electrons are in the ______nonbonding molecular orbital. These electrons can be excited to the π* _______ orbital.

Ultraviolet (UV) light is electromagnetic radiation that corresponds to wavelengths between 200 nm and 400 nm, and UV absorption causes an electron transition from the ground state to a higher energy level. In the ground state, π electrons from double bonds are in the π bonding molecular orbital, and nonbonding electrons are in the n nonbonding molecular orbital. These electrons can be excited to the π* antibonding orbital.

Vibrational modes that do not produce a net change in a ______ are not IR-active and will not produce an _______ peak in an IR spectrum.

Vibrational modes that do not produce a net change in a dipole are not IR-active and will not produce an absorbance peak in an IR spectrum.

When a battery is charging, it is an ______cell, and when it is discharging, it is a _____ cell. The difference between charging and discharging is determined by which electrode is the cathode and which is the anode. Although electron flow is in the ______ direction when a battery is charging as when it is discharging, electrons always flow from the ______ to the cathode

When a battery is charging, it is an electrolytic cell, and when it is discharging, it is a galvanic cell. The difference between charging and discharging is determined by which electrode is the cathode and which is the anode. Although electron flow is in the opposite direction when a battery is charging as when it is discharging, electrons always flow from the anode to the cathode

When a reaction occurs under conditions such that it is __________ (eg, high temperatures), it is said to be under __________ control. Under these conditions, all products form quickly and the most _______product will be favored (ie, the most negative ΔG), as it is least likely to undergo the reverse reaction.

When a reaction occurs under conditions such that it is reversible (eg, high temperatures), it is said to be under thermodynamic control. Under these conditions, all products form quickly and the most stable product will be favored (ie, the most negative ΔG), as it is least likely to undergo the reverse reaction.

When the conditions are such that a reaction is ________ (eg, low temperature), it is said to be under kinetic control, and the most favorable product is the one whose pathway has the ________activation energy. Unless the reactions have had time to complete, the __________reaction will yield the most product.

When the conditions are such that a reaction is irreversible (eg, low temperature), it is said to be under kinetic control, and the most favorable product is the one whose pathway has the lowest activation energy. Unless the reactions have had time to complete, the fastest reaction will yield the most product.

surface tension is a force induced at the interface between a liquid and a gas. The molecules in the liquid interact with each other _____ strongly than they interact with molecules in the air, causing the surface of the liquid to behave as a thin ________

surface tension is a force induced at the interface between a liquid and a gas. The molecules in the liquid interact with each other more strongly than they interact with molecules in the air, causing the surface of the liquid to behave as a thin film.

the coordination number of a metal complex refers to the number of _______ bonds formed between the central metal ion and its nearest neighboring atoms. When all of these nearest neighboring atoms are from separate molecules or ions, the number of _______ will equal the coordination number. However, if two or more of these nearest neighboring atoms are joined to the same coordinating ligand unit, then the number ________ will not equal the coordination number. In both cases, the number of nearest neighboring atoms and ________ bonds is unchanged, but the number of ligand units is different.

the coordination number of a metal complex refers to the number of coordinate bonds formed between the central metal ion and its nearest neighboring atoms. When all of these nearest neighboring atoms are from separate molecules or ions, the number of ligands will equal the coordination number. However, if two or more of these nearest neighboring atoms are joined to the same coordinating ligand unit, then the number ligands will not equal the coordination number. In both cases, the number of nearest neighboring atoms and coordinate bonds is unchanged, but the number of ligand units is different.

n metal complexes such as copper(II) glycinate, the coordination number refers to:

the number of coordinate bonds formed.

using the Faraday constant F to relate the charge of the electrolytic cell to moles of electrons n needed to reduce the metal. The charge per mole of Cd is the product of _____ and the ______ of electrons n needed to reduce cadmium, resulting in the equation: It/mol Cd=nF Solving for moles of Cd results in the equation: mol Cd=It/nF

using the Faraday constant F to relate the charge of the electrolytic cell to moles of electrons n needed to reduce the metal. The charge per mole of Cd is the product of F and the moles of electrons n needed to reduce cadmium, resulting in the equation: It/mol Cd=nF Solving for moles of Cd results in the equation: mol Cd=It/nF

How should one solve for dilution factor?

1. Solve for volume of stock solution needed to make the standard solution 2. Divide the volume of standard solution by the volume of stock solution

A reference electrode contains a known ______potential and _________. When both electrodes in a cell contain the same chemical species (a concentration cell), the electric potential difference (voltage) between the electrodes depends only on the relative concentrations of these species.

A reference electrode contains a known electric potential and concentration of ions. When both electrodes in a cell contain the same chemical species (a concentration cell), the electric potential difference (voltage) between the electrodes depends only on the relative concentrations of these species.

A disproportionation reaction is a _____reaction in which both the oxidation and the reduction occur to atoms of the same element.

A disproportionation reaction is a redox reaction in which both the oxidation and the reduction occur to atoms of the same element.

A mole is defined as the amount of a substance that contains as many particles, atoms, or ions as the number of ______ in 12 g of 12C. Experimental studies have demonstrated that there are 6.02 × 10^23 ______ in 12 g of 12C. This number is known as Avogadro's number. Moles of a substance can be converted to ions (or particles, _________, _______) using Avogadro's number, 6.02 × 1023.

A mole is defined as the amount of a substance that contains as many particles, atoms, or ions as the number of atoms in 12 g of 12C. Experimental studies have demonstrated that there are 6.02 × 1023 atoms in 12 g of 12C. This number is known as Avogadro's number. Moles of a substance can be converted to ions (or particles, molecules, atoms) using Avogadro's number, 6.02 × 1023.

A reference electrode contains a known _________and ________ of ions. When both electrodes in a cell contain the same ________ (a concentration cell), the electric potential difference (voltage) between the electrodes depends only on the ______________of these species.

A reference electrode contains a known electric potential and concentration of ions. When both electrodes in a cell contain the same chemical species (a concentration cell), the electric potential difference (voltage) between the electrodes depends only on the relative concentrations of these species.

The bond enthalpies for six selected chemical bonds are shown below. Bond Bond enthalpy ΔH°298 (kJ/mol) H―H 436 C―H 413 C=O 532 N―H 335 O―H 499 O=O 495 For a reaction in which 2 moles of H2(g) reacts with 1 mole of O2(g) to form 2 moles of H2O(g), what is the heat of the reaction? A.1367 kJ B.369 kJ C.−629 kJ D.−1996 kJ

According to Hess' law, if a reaction occurs in several steps, the heat of the reaction (overall enthalpy) is equal to the sum of the enthalpy changes for each step, because enthalpy is a state function. Accordingly, a chemical reaction can be viewed as a combined series of steps in which bonds within the reactants are broken as new bonds are formed to make the products. Forming a bond is an exothermic process that releases energy (negative enthalpy), whereas breaking a bond is an endothermic process that requires energy (positive enthalpy). As a result, the enthalpies associated with breaking and forming a given type of bond are equal in magnitude but opposite in sign. When a bond between two atoms is broken in a homolytic cleavage, the electrons within the bond are equally divided between the atoms. X—Y → X•+Y• The bond enthalpy ΔH°298 (bond dissociation energy) is the energy needed to homolytically break 1 mole of a given type of bond between two atoms in the gas phase at a temperature of 298 K.

According to the law of conservation of mass, atoms are neither _______nor ________ in a chemical reaction. The same number of each type of atom must be present on both the left and right sides of a reaction arrow. Multistep reactions that go to completion must _______ all intermediates produced before or during the final step.

According to the law of conservation of mass, atoms are neither created nor destroyed in a chemical reaction. The same number of each type of atom must be present on both the left and right sides of a reaction arrow. Multistep reactions that go to completion must consume all intermediates produced before or during the final step.

Adding ligands that can form soluble coordination complexes with metal ions in a solution can ______the solubility of ionic salts. This occurs by applying Le Châtelier's principle to disrupt the solubility equilibrium and shift the reaction toward the products.

Adding ligands that can form soluble coordination complexes with metal ions in a solution can enhance the solubility of ionic salts. This occurs by applying Le Châtelier's principle to disrupt the solubility equilibrium and shift the reaction toward the products.

Although some atoms participate only in single covalent bonding (by σ bond), other atoms are capable of participating in multiple bonds (a double or triple bond) by the addition of one or more ____ bonds. In this way, a double bond consists of ____σ bond and ____ π bond, and a triple bond consists of ____σ bond and _____ π bonds.

Although some atoms participate only in single covalent bonding (by σ bond), other atoms are capable of participating in multiple bonds (a double or triple bond) by the addition of one or more π bonds. In this way, a double bond consists of one σ bond and one π bond, and a triple bond consists of one σ bond and two π bonds.

An experimental control is a measurement taken with all experimental conditions in place except the ________ variables. The control setup allows for baseline measurements of _______ variables in the absence of independent variables, allowing for a more accurate assessment of the ________variables' effects.

An experimental control is a measurement taken with all experimental conditions in place except the independent variables. The control setup allows for baseline measurements of dependent variables in the absence of independent variables, allowing for a more accurate assessment of the independent variables' effects.

Applying the law of mass action, an equilibrium constant Keq can be expressed for a reaction as a ratio of the molar concentrations of the products over the reactants, each raised to the power of its respective balanced reaction coefficient. Because the concentration of the solvent is much _______ than the concentration of all other species in the solution, the solvent is relatively _________ and is omitted from the Keq expression

Applying the law of mass action, an equilibrium constant Keq can be expressed for a reaction as a ratio of the molar concentrations of the products over the reactants, each raised to the power of its respective balanced reaction coefficient. Because the concentration of the solvent is much greater than the concentration of all other species in the solution, the solvent is relatively constant and is omitted from the Keq expression

As a sublevel is filled, electrons form pairs only after all orbitals contain at least one electron. The magnetic properties of an atom (or ion) depend on whether or not unpaired electrons remain after all electrons are assigned to an orbital. If unpaired electrons remain, then the atom is ________ and the unpaired electrons will interact with a magnetic field. If all electrons are paired, then the electrons will not interact with a magnetic field and the atom is __________

As a sublevel is filled, electrons form pairs only after all orbitals contain at least one electron. The magnetic properties of an atom (or ion) depend on whether or not unpaired electrons remain after all electrons are assigned to an orbital. If unpaired electrons remain, then the atom is paramagnetic and the unpaired electrons will interact with a magnetic field. If all electrons are paired, then the electrons will not interact with a magnetic field and the atom is diamagnetic.

As stated by the Pauli exclusion principle, each orbital within a subshell can hold a maximum of ______electrons, which must have ______ spins. These electrons are represented by arrows and the spin is indicated by the orientation of the arrow (up or down). The occupied orbitals are often represented by ______ or boxes. Hund's rule states that electrons fill orbitals in such a way as to maximize the number of unpaired electrons.

As stated by the Pauli exclusion principle, each orbital within a subshell can hold a maximum of two electrons, which must have opposite spins. In schematic representations, these electrons are represented by arrows and the spin is indicated by the orientation of the arrow (up or down). The occupied orbitals are often represented by blanks or boxes. Hund's rule states that electrons fill orbitals in such a way as to maximize the number of unpaired electrons.

As the orbitals are filled, Hund's rule states that electrons remain _____ until pairing is required to add another electron.

As the orbitals are filled, Hund's rule states that electrons remain unpaired until pairing is required to add another electron.

At equilibrium, the rates of dissolution and precipitation are _______, and the solution is _______ with the ions of the reaction. At concentrations _________Ksp, the ions combine and ___________.

At equilibrium, the rates of dissolution and precipitation are equal, and the solution is saturated with the ions of the reaction. At concentrations above Ksp, the ions combine and precipitate.

Rules of resonance : Atoms never move, only _________ All resonance structures must have the same total number of __________. The octet rule must be obeyed for ______- and ______-row elements. Only electrons in _____ bonds or ______ can move, not electrons in sigma bonds. Shifting of electrons should generally only be to adjacent atoms when going from one resonance structure to another. The ______of the molecule must not change; however, the formal charge of the constituent atoms can change.

Atoms never move, only electrons. All resonance structures must have the same total number of valence electrons. The octet rule must be obeyed for first- and second-row elements. Only electrons in pi bonds or lone pairs can move, not electrons in sigma bonds. Shifting of electrons should generally only be to adjacent atoms when going from one resonance structure to another. The overall charge of the molecule must not change; however, the formal charge of the constituent atoms can change.

Assume that helium behaves as an ideal gas. What is the estimated density of 1.0 g of helium gas at a temperature of 27 °C and a pressure of 3.0 atm? (Note: Use R = 0.0821 L∙atm∙mol−1∙K−1) A.1.2 × 10−4 g/mL B.4.9 × 10−4 g/mL C.1.4 × 10−3 g/mL D.5.4 × 10−3 g/mL

B

Which of the following element groups is NOT included in the representative elements? A.Group 1 B.Group 3 C.Group 13 D.Group 18

B

Because of the shapes of the orbitals involved, bond length tends to________ (relative to a triple bond) as the number of π bonds decreases Because σ bonds are made by an end-to-end orbital overlap, free rotation around the bond between the two σ-bonded atoms _____ be achieved while maintaining the orbital overlap. Therefore, decreasing the number of pi bonds also _______ the rigidity of the bond between the atoms

Because of the shapes of the orbitals involved, bond length tends to increase (relative to a triple bond) as the number of π bonds decreases Because σ bonds are made by an end-to-end orbital overlap, free rotation around the bond between the two σ-bonded atoms can be achieved while maintaining the orbital overlap. Therefore, decreasing the number of π bonds also decreases the rigidity of the bond between the atoms

Because the addition of shells has a strong effect on _____, changes in atomic radius down a group are _______ pronounced than for those across a period.

Because the addition of shells has a strong effect on shielding, changes in atomic radius down a group are more pronounced than for those across a period.

Bond enthalpy is the energy needed to homolytically break 1 mole of a given type of bond between two atoms in the gas phase at 298 K. According to Hess' law, a reaction can be assessed as a series of ________ bond-breaking and ________ bond-forming steps, and the heat of the reaction is equal to the sum of the enthalpy changes for each step.

Bond enthalpy is the energy needed to homolytically break 1 mole of a given type of bond between two atoms in the gas phase at 298 K. According to Hess' law, a reaction can be assessed as a series of endothermic bond-breaking and exothermic bond-forming steps, and the heat of the reaction is equal to the sum of the enthalpy changes for each step.

By the Brønsted-Lowry definitions, an acid is a molecule that ________a proton (H+ ion), and a base is a molecule that _______ a proton. Accordingly, a Lewis acid is defined as an electron pair _______, and a Lewis base is defined as an electron pair __________

By the Brønsted-Lowry definitions, an acid is a molecule that donates a proton (H+ ion), and a base is a molecule that accepts a proton. Accordingly, a Lewis acid is defined as an electron pair acceptor, and a Lewis base is defined as an electron pair donor.

Compare Na+ and Mg+2 in terms of size, which one is smaller?

Cations are generally smaller than neutral atoms and anions in an isoelectronic series, but Na+ is not the smallest because it has one less proton than Mg2+ (lesser Zeff to pull the electrons toward the nucleus).

The regulation of mineral ions in the cellular fluids of biological systems is performed by ion pumps that selectively transport ions of specific size and charge across cellular membranes. Which of the following isoelectronic species is the smallest ion? A.Na+ B.F− C.Mg2+ D.O2−

Compared to the neutral atom of a given element, its cation will be smaller but its anion will be larger. Losing electrons to form a cation causes the remaining electrons to experience a greater effective nuclear charge (Zeff), pulling the electrons closer to the nucleus. Conversely, gaining electrons to form an anion produces greater electronic repulsion and nuclear shielding (lesser Zeff), which pushes electrons farther from the nucleus. (Na+, F−, Mg2+, and O2− ions are isoelectronic (have the same number of electrons), but because the number of protons is different in each ion, the electrons in each ion experience a different Zeff. Therefore, in an isoelectronic series, ionic radii decrease with increasing atomic number. Because magnesium has the highest atomic number (greatest number of protons) in the isoelectronic series, Zeff is greatest in this ion, making it the smallest within the given series.)

When oxalate anions, C2O42−, are added to a solution of [Fe(H2O)6]3+, the formation of [Fe(C2O4)3]3− occurs in a series of steps that together result in the following overall reaction: [Fe(H2O)6]3+(aq) + 3 C2O42−(aq) → [Fe(C2O4)3]3−(aq) + 6 H2O(l) During the first step of the reaction, two new coordinate bonds are formed to produce an intermediate ion of: A.[Fe(H2O)4(C2O4)]+(aq). B.[Fe(H2O)2(C2O4)2]−(aq). C.[Fe(C2O4)3]3−(aq). D.[Fe(H2O)5(C2O4)]2−(aq).

Complex ions (coordination complexes) consist of a central metal ion surrounded by one or more ions or molecules called ligands that are bound to the metal center by coordinate bonds. The coordinate bonds form because the ligands surrounding the metal center act as Lewis bases and donate a lone pair of electrons to the metal center, which acts as a Lewis acid. These Lewis acid-base coordinations hold the complex together, but stronger Lewis bases can displace weaker Lewis bases as ligands within the complex. In the [Fe(H2O)6]3+ complex ion, an uncharged water molecule serving as a ligand is a weak Lewis base and can be displaced by the oxalate (C2O42−) anion, a stronger Lewis base. Each C2O42− anion displaces two water molecules and decreases the overall charge of the resulting complex ion by −2. Displacement of water within the complex occurs in a stepwise sequence. In the first step, two water molecules are displaced from [Fe(H2O)6]3+ by a single C2O42− anion to form an intermediate complex ion: [Fe(H2O)6]3+(aq) + C2O42−(aq) → [Fe(H2O)4(C2O4)]+(aq) + 2 H2O(l) In the second and third steps, additional C2O42− anions displace the remaining water ligands to form the final product. (Choice B) This is the intermediate ion formed during the second step of the reaction, not the first step. (Choice C) This is not an intermediate ion; it is the end product formed during the final third step of the overall net reaction. (Choice D) Both the ion charge and this formula are incorrect. The first step adds one C2O42− ion to the complex, but each oxalate ion displaces two water molecules and decreases the overall charge of the complex by −2.

Covalent bonds are formed by sharing electrons between atoms through the overlap of atomic orbitals in an end-to-end or side-to-side configuration. Multiple bonds formed by s and p orbitals consist of one ____ bond and one or more π bonds, and the overall energy of a bond tends to _____ relative to a single bond with each additional π bond.

Covalent bonds are formed by sharing electrons between atoms through the overlap of atomic orbitals in an end-to-end or side-to-side configuration. Multiple bonds formed by s and p orbitals consist of one σ bond and one or more π bonds, and the overall energy of a bond tends to increase relative to a single bond with each additional π bond.

Covalent bonds formed by sharing electrons though an ________ overlap of orbitals are called sigma (σ) bonds, whereas covalent bonds made by the side-to-side overlap of p orbitals are called ______ bonds. Although some atoms participate only in single covalent bonding (by a σ bond), other atoms can participate in double or triple bonds by the addition of π bonds. As such, a double bond consists of one _______bond and ______ π bond, and a triple bond consists of _____ σ bond and ______ π bonds.

Covalent bonds formed by sharing electrons though an end-to-end overlap of orbitals are called sigma (σ) bonds, whereas covalent bonds made by the side-to-side overlap of p orbitals are called pi (π) bonds. Although some atoms participate only in single covalent bonding (by a σ bond), other atoms can participate in double or triple bonds by the addition of π bonds. As such, a double bond consists of one σ bond and one π bond, and a triple bond consists of one σ bond and two π bonds.

When ammonia burns in air, nitrogen dioxide and water are produced according to the reaction below: 4 NH3(g) + 7 O2(g) → 4 NO2(g) + 6 H2O(l) At 0 °C and 1 atm pressure, burning 44.8 L of ammonia requires: A.6/7 moles O2 B.8/7 moles O2 C.7/4 moles O2. D.7/2 moles O2.

D Under conditions of standard temperature and pressure (STP), which is defined as 0 °C and 1 atm of pressure, 1 mole of gas occupies a volume of 22.4 L. Mole ratios from balanced chemical reactions can be used to relate the moles of a given gas to the moles of other reaction species.

Electron affinity is defined as the change in energy resulting from _______ an electron to a neutral atom of an element X in the ______ state to form an anion with a −1 charge: X(g) + e− → X−(g) When a stable anion is formed, energy is _______, which results in a _________value for the change in energy. Therefore, elements with a more _______ electron affinity more readily accept the _________of an electron.

Electron affinity is defined as the change in energy resulting from adding an electron to a neutral atom of an element X in the gas state to form an anion with a −1 charge: X(g) + e− → X−(g) When a stable anion is formed, energy is released, which results in a negative value for the change in energy. Therefore, elements with a more negative electron affinity more readily accept the addition of an electron.

Every additional bond formed between two atoms after a sigma bond is a _____ bond which are created by the sideways overlap of ______ orbitals along a plane ______r to (ie, above and below) the internuclear axis. Because the overlap in electron density is not as efficient as for sigma bonds, pi bonds exist in a______ energy state and are not as _____ as sigma bonds. As a result, they require _____ energy to be broken than sigma bonds (ie, they have a_______ dissociation energy)

Every additional bond formed between two atoms after a sigma bond is a pi bond. Pi bonds are created by the sideways overlap of p orbitals along a plane perpendicular to (ie, above and below) the internuclear axis. Because the overlap in electron density is not as efficient as for sigma bonds, pi bonds exist in a higher energy state and are not as stable as sigma bonds. As a result, they require less energy to be broken than sigma bonds (ie, they have a smaller dissociation energy)

For a process to be spontaneous, the Gibbs free energy ΔG°′ must be ________ . Gibbs free energy is ______ proportional to standard reduction potential, as described by the Nernst equation, ΔG°′ = −nF ΔE0′.

For a process to be spontaneous, the Gibbs free energy ΔG°′ must be negative. Gibbs free energy is inversely proportional to standard reduction potential, as described by the Nernst equation, ΔG°′ = −nF ΔE0′.

Formal charge and oxidation state are two different ways of accounting for electrons between atoms. Based on the Lewis structure of the ClO− anion, which of the following pairs of values corresponds to the formal charge of the chlorine atom and the oxidation state of the oxygen atom, respectively? A.+1, −1 B.0, −1 C.0, −2 D.−1, −2

Formal charge and oxidation state (oxidation number) are two different methods used to account for electrons around an atom. Formal charge and oxidation state are not necessarily equal because these values signify different aspects related to chemical bonding. Formal charge assesses the allocation of charge to the atoms in a Lewis structure based on the bonding configuration of the atoms. Oxidation state assesses the gain or loss of electrons by an atom (relative to the elemental valence configuration) due to bond formation. (ANS: B)

Moving down the column, the alkaline-earth metals are observed to give increasingly vigorous reactions when forming ionic bonds with nonmetals (Reactions 1-3). Based on atomic properties, this trend in reactivity is best explained by comparing: A.the energy required to remove an electron from each atom. B.the tendency of each atom to attract electrons within a bond. C.the extent to which the electron cloud of each atom can be distorted by an external charge.[14%] D.the energy released when an electron is added to each atom.

Formation of an ionic bond between an alkaline-earth metal and a nonmetal requires the valence electrons of the metal atom to be removed and transferred to the nonmetal atom. Of the four properties previously discussed, only ionization energy quantifies how easily electrons are removed from an atom. Moving down the alkaline-earth metal column, ionization energy decreases. This makes removing an electron more favorable and increases reactivity. (Choice B) Although the reactivity of the alkaline-earth metals does increase as electronegativity decreases, this correlation does not explain the cause of the reactivity trend. IF Reactions proceed by forming ions (ionization); electronegativity is not the best property to explain the reactivity trend. (Choice C) If reactions depend on the transfer of electrons (ionic bond formation) rather than on the distortion of the electron cloud. (Choice D) Electrons must be removed from (not added to) the alkaline-earth metals for Reactions to occur.

Hund's rule states that orbital filling maximizes the number of _______ electrons. _______ atoms and molecules have unpaired electrons that align parallel to an applied magnetic field; these species are weakly attracted to magnets. In contrast, _________ atoms and molecules have no unpaired electrons; these species are repelled by magnets.

Hund's rule states that orbital filling maximizes the number of unpaired electrons. Paramagnetic atoms and molecules have unpaired electrons that align parallel to an applied magnetic field; paramagnetic species are weakly attracted to magnets. In contrast, diamagnetic atoms and molecules have no unpaired electrons; these species are repelled by magnets.

Hybrid orbitals are formed by combining the ______ for a given atom, forming new electron domains. To identify the type of hybrid orbital in an atom, determine its number of electron domains by summing the _____bonds and __________.

Hybrid orbitals are formed by combining the atomic orbitals for a given atom, forming new electron domains. To identify the type of hybrid orbital in an atom, determine its number of electron domains by summing the sigma bonds and lone pairs.

Hybrid orbitals are formed by combining the atomic _____ for a given atom, forming new electron domains. To identify the type of hybrid orbital in an atom, determine its number of _____ domains by summing the _____ bonds and ______ pairs. The sum of s and p superscripts on the hybrid name should match this number: sp3-hybridized atoms have four electron domains, sp2 have three, and sp have two

Hybrid orbitals are formed by combining the atomic orbitals for a given atom, forming new electron domains. To identify the type of hybrid orbital in an atom, determine its number of electron domains by summing the sigma bonds and lone pairs. The sum of s and p superscripts on the hybrid name should match this number: sp3-hybridized atoms have four electron domains, sp2 have three, and sp have two

If peak protection of a sunscreen B10 is at 297 nm, it means the active compound most commonly absorbs photons of ________. Because an atom or molecule can only absorb energy exactly equal to the difference between two energy levels, the difference in energy ΔE between the ground state and the most commonly occurring photo-excited state for the active compound in sunscreen

If peak protection of a sunscreen B10 is at 297 nm, it means the active compound most commonly absorbs photons of that wavelength. Because an atom or molecule can only absorb energy exactly equal to the difference between two energy levels, the difference in energy ΔE between the ground state and the most commonly occurring photo-excited state for the active compound in sunscreen

In a _______ reaction, the same element (at a given oxidation state) undergoes both oxidation and reduction, with some of the atoms being oxidized and other atoms of the same element being reduced.

In a disproportionation reaction, the same element (at a given oxidation state) undergoes both oxidation and reduction, with some of the atoms being oxidized and other atoms of the same element being reduced.

In all forms of beta decay, the mass number remains _______, while the atomic number increases (_______-decay) or ___________(β+-decay and electron capture) by 1. β−-decay converts a neutron into a __________ and emits an _________. β+-decay and electron capture convert a _________ into a ________ (the opposite of a β−-decay).

In all forms of beta decay, the mass number remains unchanged, while the atomic number increases (β−-decay) or decreases (β+-decay and electron capture) by 1. β−-decay converts a neutron into a proton and emits an electron. β+-decay and electron capture convert a proton into a neutron (the opposite of a β−-decay).

In chelate formation reactions, a ______ cation and a _____ react to form one or more rings via a pincer-like coordinate bonding arrangement. In an oxidation-reduction (redox) reaction, the ________ of some atoms change during the conversion of the reactants to the products.

In chelate formation reactions, a metal cation and a ligand react to form one or more rings via a pincer-like coordinate bonding arrangement. In an oxidation-reduction (redox) reaction, the oxidation states of some atoms change during the conversion of the reactants to the products.

In coordination chemistry, metal ions such as Gd3+ can act as Lewis _____ because they have empty valence orbitals that can readily accept ______. Molecules or atoms with lone pairs of electrons act as Lewis ______ and coordinate to the metal ion, forming a complex ion; these electron-donating groups are referred to as _______.

In coordination chemistry, metal ions such as Gd3+ can act as Lewis acids because they have empty valence orbitals that can readily accept electrons. Molecules or atoms with lone pairs of electrons act as Lewis bases and coordinate to the metal ion, forming a complex ion; these electron-donating groups are referred to as ligands.

In general, a C-O single bond has ____ energy than a C=O double bond, and a C=O double bond has ____energy than a C≡O triple bond.

In general, a C-O single bond has less energy than a C=O double bond, and a C=O double bond has less energy than a C≡O triple bond.

zone (O3) in the atmosphere protects against harmful UV radiation. Its formation proceeds in two steps and is initiated when molecular oxygen (O2) splits into two oxygen atoms upon absorption of UV light. Which of the following would be the second step if ozone formation goes to completion? A.O + O2 → O3 B.2O + 2O2 → 2O3 C.3O2 → 2O3 D.O + 2O2 → O3

In the formation of ozone (O3), first, one molecule of oxygen (O2) is split into two oxygen atoms as intermediates (O2 → 2O). The oxygen atoms are then consumed as each reacts with an oxygen molecule to form ozone. For the reaction to go to completion, the two oxygen atoms must combine with two O2 molecules to form two ozone molecules (2O + 2O2 → 2O3) in the second step. (Choice A) O + O2 → O3 correctly shows the reaction of one oxygen atom with one O2 molecule to form one ozone molecule. However, the question states that two oxygen atoms are formed as intermediates in the initial step, both of which must be consumed for the reaction to go to completion.

Ionic radii tend to _________ in size across a period (row) of the periodic table (left to right) and _______ moving down a group (column). This trend occurs for metal _________, and then resets and repeats for ________beginning near the division between metals and nonmetals, past which anions tend to preferentially form.

Ionic radii tend to decrease in size across a period (row) of the periodic table (left to right) and increase moving down a group (column). This trend occurs for metal cations, and then resets and repeats for anions beginning near the division between metals and nonmetals, past which anions tend to preferentially form.

When comparing atoms across the same row of the periodic table, which of the following groups will contain the atom with the lowest second ionization energy? A.Group 1 B.Group 2 C.Group 14 D.Group 16

Ionization energy is the energy required to remove an electron (e−) from an atom or ion (measured in the gas state). The first ionization energy refers to the removal of the first electron from a neutral atom of an element (X): X + energy → X+ + e− The second ionization energy refers to the removal of a second electron: X+ + energy → X+2 + e− Loosely bound electrons (valence electrons) are removed first before any core electrons. Accordingly, removing a core electron takes more energy than does removing a valence electron. On the periodic table, metals generally have a lower first ionization energy than nonmetals, and first ionization energies tend to increase across a row and decrease down a column. The same is true for the second ionization energy except when the second electron being removed is not a valence electron. If comparing elements in period (row) three, the nonmetals Si (Group 14) and S (Group 16) are farther to the right in the period, and both have a higher second ionization energy than the metals Na and Mg. However, the second ionization energy of Na (Group 1) is much higher than that of Mg (Group 2) because Na has only one valence electron and removing a second electron from Na requires the loss of a core electron. The availability of a second valence electron gives Mg (Group 2) the lowest second ionization energy.

Loosely bound electrons (valence electrons) are removed first before any core electrons. Accordingly, removing a core electron takes _______ energy than does removing a valence electron. On the periodic table, metals generally have a _______first ionization energy than nonmetals, and first ionization energies tend to _______ across a row and ________ down a column. The same is true for the second ionization energy except when the second electron being removed is not a valence electron.

Loosely bound electrons (valence electrons) are removed first before any core electrons. Accordingly, removing a core electron takes more energy than does removing a valence electron. On the periodic table, metals generally have a lower first ionization energy than nonmetals, and first ionization energies tend to increase across a row and decrease down a column. The same is true for the second ionization energy except when the second electron being removed is not a valence electron.

Losing electrons to form a cation causes the remaining electrons to experience a _______effective nuclear charge Zeff, ______ the electrons _______ to the nucleus. Conversely, gaining electrons to form an anion produces ______ electronic repulsion and nuclear shielding (_______ Zeff), which pushes electrons ________from the nucleus.

Losing electrons to form a cation causes the remaining electrons to experience a greater effective nuclear charge Zeff, pulling the electrons closer to the nucleus. Conversely, gaining electrons to form an anion produces greater electronic repulsion and nuclear shielding (lesser Zeff), which pushes electrons farther from the nucleus.

Many atomic properties are associated with electrons. Four such properties are polarizability, electronegativity, electron affinity, and ionization energy. ________ is the extent to which an electron cloud of an atom can be distorted by an external charge or by an applied electric field to produce a dipole. ________ is the tendency of an atom to attract electrons within a bond. _______ ________ assesses the tendency of an atom to accept an additional electron by measuring the energy change when an electron is added to an atom. _________ __________ (the opposite of electron affinity) measures the energy required to remove an electron from an atom.

Many atomic properties are associated with electrons. Four such properties are polarizability, electronegativity, electron affinity, and ionization energy. Polarizability is the extent to which an electron cloud of an atom can be distorted by an external charge or by an applied electric field to produce a dipole. Electronegativity is the tendency of an atom to attract electrons within a bond. Electron affinity assesses the tendency of an atom to accept an additional electron by measuring the energy change when an electron is added to an atom. Ionization energy (the opposite of electron affinity) measures the energy required to remove an electron from an atom.

Rules for recognizing the resonance of a molecule

Molecules can be represented by more than one Lewis structure if their electrons are delocalized, meaning they can be in different locations. The collection of these Lewis structures is known as resonance structures.

Multiple covalent bonds formed by s and p orbitals consist of one _____ bond (end-to-end orbital overlap) and one or more ______ bonds (side-to-side p orbital overlap). Decreasing the number of pi bonds between two atoms _______ bond length, _______ bond rigidity, and _______ the overall bond energy and strength.

Multiple covalent bonds formed by s and p orbitals consist of one σ bond (end-to-end orbital overlap) and one or more π bonds (side-to-side p orbital overlap). Decreasing the number of π bonds between two atoms increases bond length, decreases bond rigidity, and decreases the overall bond energy and strength.

NADH can be oxidized and therefore serves as a _______ agent. Furthermore, NADH is not required for _______. Instead, NAD+ serves as an ______ agent for catabolic reactions and is reduced to NADH in the process. NADH enters the ETC as a ______agent after catabolic oxidation of fuel molecules and provides the _______ for the production of ATP.

NADH can be oxidized and therefore serves as a reducing agent. Furthermore, NADH is not required for catabolism. Instead, NAD+ serves as an oxidizing agent for catabolic reactions and is reduced to NADH in the process. NADH enters the ETC as a reducing agent after catabolic oxidation of fuel molecules and provides the energy for the production of ATP.

Resonance structures are ______ dot structures of a given molecule in which _______ have been delocalized. Acceptable resonance structures move only _______ and generally only to adjacent atoms, keep the number of ________ electrons constant, obey the ______ rule, do not break _____ bonds, and keep the overall _______ of the molecule constant.

Resonance structures are Lewis dot structures of a given molecule in which electrons have been delocalized. Acceptable resonance structures move only electrons and generally only to adjacent atoms, keep the number of valence electrons constant, obey the octet rule, do not break sigma bonds, and keep the overall charge of the molecule constant.

______ are indicated using the principal quantum number n, which relates to the distance of an _____ from the nucleus. _______ are labeled by type (s, p, d, or f ), which relates to the shapes of the occupied orbitals present. Electron configurations are listed sequentially in order of increasing energy (_______ principle).

Shells are indicated using the principal quantum number n, which relates to the distance of an orbital from the nucleus. Subshells are labeled by type (s, p, d, or f ), which relates to the shapes of the occupied orbitals present. Electron configurations are listed sequentially in order of increasing energy (Aufbau principle).

Sigma bonds are _____ in energy, _______ stable, and have a _______ dissociation energy than π bonds. Although individual π bonds are _______ than σ bonds, double and triple bonds are composed of both σ and π bonds and are therefore _________overall than a single bond.

Sigma bonds are lower in energy, more stable, and have a greater dissociation energy than π bonds. Although individual π bonds are weaker than σ bonds, double and triple bonds are composed of both σ and π bonds and are therefore stronger overall than a single bond.

Sigma bonds, which are generally the first bond formed between atoms, are created when the electron bonding pair is between the two atoms such that their atomic orbitals overlap end-to-end along the ______ axis. Because of the efficient overlap of the atomic orbitals, sigma bonds are _____ in energy and are very _______

Sigma bonds, which are generally the first bond formed between atoms, are created when the electron bonding pair is between the two atoms such that their atomic orbitals overlap end-to-end along the internuclear axis. Because of the efficient overlap of the atomic orbitals, sigma bonds are low in energy and are very stable.

In pure water at 25 °C, the concentration of a saturated solution of CuF2 is 7.4 × 10−3 M. If measured at the same temperature, what is the concentration of a saturated solution of CuF2 in aqueous 0.20 M NaF? A.8.1 × 10−6 M B.4.0 × 10−5 M C.7.4 × 10−3 M D.6.4 × 10−2 M

Solubility refers to the maximum amount of a compound that can dissolve per unit volume of a solvent at a particular temperature. When an ionic compound is placed in water, the composite ions will dissociate to some extent into the solution and establish an equilibrium. The solubility product constant Ksp of the equilibrium provides a measure of the solubility. If a solution contains two salts that have an ion in common, the common ion supplied by one salt produces a common ion effect that stresses the product side of the equilibrium of the other salt and shifts the equilibrium to the left. Accordingly, for both salts the solubilities decrease. CuF2(s) ⇄ Cu2+(aq)+2 F−(aq) NaF(s) ⇄ Na+(aq)+F−(aq) When dissolving CuF2 in 0.20 M NaF, initially there is no Cu2+ or F− in solution from CuF2 but there is 0.20 M F− from the NaF. If an amount x of CuF2 subsequently dissolves, the changes and equilibrium concentrations can be evaluated as shown above. Placing these equilibrium values into the Ksp expression for CuF2 gives Ksp=[Cu2+][F−]2=(x)(0.20+2x)2 Because the Ksp of CuF2 is small, it can be assumed that x is very small compared to 0.20 M. In this case, (0.20 + 2x) can be approximated as 0.20 M to simplify the calculation: Ksp=(x)(0.20)2=0.040x As stated in the passage, the Ksp of CuF2 is 1.6 × 10−6. Substituting this value of the Ksp into the equation and solving for x gives 1.6×10−6=0.040x x=4.0×10−5 M CuF2 Therefore, the concentration of a saturated solution of CuF2 in aqueous 0.20 M NaF is 4.0 × 10−5 M, which is less than its saturated concentration in pure water.

Standard reduction potentials (ΔE0′) indicate whether a molecule will spontaneously gain or lose electrons, and are related to the Gibbs free energy (ΔG°′). In a spontaneous process, ΔE0′ is ________, ΔG°′ is ________, and electrons flow from molecules with ________ reduction potential to molecules with ________ reduction potential.

Standard reduction potentials (ΔE0′) indicate whether a molecule will spontaneously gain or lose electrons, and are related to the Gibbs free energy (ΔG°′). In a spontaneous process, ΔE0′ is positive, ΔG°′ is negative, and electrons flow from molecules with low reduction potential to molecules with high reduction potential.

If the ETC is a spontaneous process, what MUST be true about the redox reactions within each of the four complexes?

Standard reduction potentials are indicative of whether a molecule will spontaneously gain or lose electrons. In a spontaneous process, ΔE0′ is positive. The ETC is a series of spontaneous processes, so all of the standard reduction potentials must fall within the range of NAD+ (E0′ = −0.320 V) and O2 (E0′ = 0.816 V), and each step in the chain must have a larger ΔE0′ than the previous step.

Stronger bonds require more energy to break (dissociate) than weaker bonds. The overall strength of a bond results from the sum of all _____and _______ bonding contributors. As a result, when comparing bonds involving the same two types of atoms, a _____ bond is stronger than a double bond, and a double bond is stronger than a _____ bond because double and _____ bonds are composed of both σ and _____bonds.

Stronger bonds require more energy to break (dissociate) than weaker bonds. The overall strength of a bond results from the sum of all σ and π bonding contributors. As a result, when comparing bonds involving the same two types of atoms, a triple bond is stronger than a double bond, and a double bond is stronger than a single bond because double and triple bonds are composed of both σ and π bonds.

The difference in _________ between two covalently bonded atoms is proportional to (and indicative of) the magnitude of the dipole moment along the bond between the atoms. ________differences in electronegativity invoke larger dipole moments between atoms.

The difference in electronegativity between two covalently bonded atoms is proportional to (and indicative of) the magnitude of the dipole moment along the bond between the atoms. Larger differences in electronegativity invoke larger dipole moments between atoms.

The difference in energy between the _______ and _______ points is the change in Gibbs free energy, ΔG. If the reaction's overall ΔG is negative, the products will have a ________ Gibbs free energy than the reactants and the reaction is spontaneous (________). If the reaction's overall ΔG is positive, the products will have a ______ Gibbs free energy than the reactants and the reaction is nonspontaneous (________).

The difference in energy between the starting and ending points is the change in Gibbs free energy, ΔG. If the reaction's overall ΔG is negative, the products will have a lower Gibbs free energy than the reactants and the reaction is spontaneous (exergonic). If the reaction's overall ΔG is positive, the products will have a higher Gibbs free energy than the reactants and the reaction is nonspontaneous (endergonic).

The electron configurations of the alkaline-earth metals end with a completely filled ______-block. Therefore, the electrons occupying the corresponding ______ orbital in the respective valence shells are paired. Accordingly, Ca and Sr have no unpaired electrons and are both diamagnetic. The Ca+2 ion results from losing both electrons from the valence shell, but because all the shells below the valence shell are fully filled (no unpaired electrons), Ca+2 is also ________

The electron configurations of the alkaline-earth metals end with a completely filled s-block. Therefore, the electrons occupying the corresponding s orbital in the respective valence shells are paired. Accordingly, Ca and Sr have no unpaired electrons and are both diamagnetic (Numbers I and III). The Ca+2 ion results from losing both electrons from the valence shell, but because all the shells below the valence shell are fully filled (no unpaired electrons), Ca+2 is also diamagnetic

The energy of a ______ is given by Ephoton=hc/λ. For a molecule or atom to transition from ground to an excited state, it must absorb a single ____ with energy exactly equal to the energy difference between the ground and excited states.

The energy of a photon is given by Ephoton=hc/λ. For a molecule or atom to transition from ground to an excited state, it must absorb a single photon with energy exactly equal to the energy difference between the two states.

The equilibrium constant of any chemical reaction describes the _________ of products to reactants once _________ is achieved. The solubility product constant Ksp is a special equilibrium constant used for __________compounds in solution. It does not include a denominator because the reactant (magnesium metal, in this case) is a solid. The amount of solid present does not affect the equilibrium.

The equilibrium constant of any chemical reaction describes the molar ratio of products to reactants once equilibrium is achieved. The solubility product constant Ksp is a special equilibrium constant used for slightly soluble compounds in solution. It does not include a denominator because the reactant (magnesium metal, in this case) is a solid. The amount of solid present does not affect the equilibrium.

What are the formulas for formal charge and oxidation state?

The formal charge (FC) accounting method assumes that the electrons in a covalent bond are shared equally, and FC is calculated as: FC=(Groupvalence)−(Nonbondingelectrons)−1/2(Bondingelectrons) The oxidation state (OS) accounting method assigns all electrons in a given bond to the most electronegative atom of the bond, and OS is calculated as: OS=(Groupvalence)−(Nonbondingelectrons)−(Bondingelectrons)

Shiny nickel metal granules added to orange liquid bromine mixed in alcohol produced a combination reaction yielding a blue-green solution of nickel(II) bromide. In the reaction between Ni and Br2: A.bromine forms a chelate with nickel. B.nickel undergoes an oxidation-reduction reaction with bromine. C.the reaction forms a precipitate of nickel(II) bromide. D.nickel and bromine participate in a Brønsted-Lowry acid-base neutralization.

The given reaction between Ni and Br2 is a combination reaction in which two reactants form a single ionic product, NiBr2. The assigned oxidation states for the elements in this reaction show that nickel goes from an oxidation state of zero in its elemental metal form to a state of +2 in the product (an oxidation), and bromine goes from an oxidation state of zero to a state of −1 (a reduction). Therefore, in addition to being a combination reaction, the reaction between Ni and Br2 is also an oxidation-reduction reaction. The reaction is not a chelate formation reaction because nickel(II) bromide is an ionic compound and does not have a ringed structure formed from pincer-like coordinate bonds between the metal and a ligand.

Assume that the pressure in a 1500 L monoplace chamber is increased from 1 ATA to 2 ATA. Which expression gives the number of moles of oxygen that is added to the chamber if the temperature remains constant at 27 °C? A.(4.5 × 105)R B.10/R C.5/R D.0.2R

The ideal gas law combines the relationships described by Boyle's law, Charles' law, and Avogadro's law into a single formula describing the behavior of an ideal gas under a given set of conditions. The ideal gas law relates pressure P (atm), volume V (L), n (moles), and temperature T (K) via the universal gas constant R, which equals 0.08206 L atm mol−1 K−1: PV=nRT This relationship provides a useful model to approximate the behavior of real gases. However, when doing calculations, it is important to keep the units of measurement consistent with those of R. In this question, the temperature of the monoplace chamber is given in degrees Celsius, but R is in terms of Kelvin, so the temperature must be converted to units of Kelvin: 27°C+273 K=300 K In addition, R is stated in terms of atm of pressure, but the question gives pressure in units of ATA (atmospheres absolute). According to the passage, 1 ATA equals 1 atm. The change in pressure is 2 ATA − 1 ATA = 1 ATA; therefore, this is equivalent to 1 atm.

The more ______ the electron affinity, the easier it is to add an electron to the valence shell of an atom. In general, the electron affinity of nonmetals is more ______ than that of metals.

The more negative the electron affinity, the easier it is to add an electron to the valence shell of an atom. In general, the electron affinity of nonmetals is more negative than that of metals.

Adding electrons to nonmetals is: A.not possible for most nonmetals. B.energetically similar to adding electrons to metals. C.easier than adding electrons to metals. D.more difficult than adding electrons to metals.

The more negative the electron affinity, the more readily an atom accepts the addition of an electron. Most nonmetals tend to accept an additional electron more readily than most metals. ANS: C

The overall energy of a bond is the sum of the energies of all ___ and ______ bonding contributors. Therefore, the overall bond energy and bond strength tend to _____(relative to a triple bond) as the number of π bonds decreases

The overall energy of a bond is the sum of the energies of all σ and π bonding contributors. Therefore, the overall bond energy and bond strength tend to decrease (relative to a triple bond) as the number of π bonds decreases

The overall energy of a bond is the sum of the energies of all ____ and _____ bonding contributors. When comparing single, double, and triple covalent bonds involving the same two types of atoms, the overall bond energy tends to _______(relative to a single bond) with each additional π bond. This is due in part to increased electron _______between the atoms that participate in multiple bonds.

The overall energy of a bond is the sum of the energies of all σ and π bonding contributors. When comparing single, double, and triple covalent bonds involving the same two types of atoms, the overall bond energy tends to increase (relative to a single bond) with each additional π bond. This is due in part to increased electron density between the atoms that participate in multiple bonds.

The principal quantum number is related to the ______ of an orbital from the nucleus, whereas the subshells are related to orbital _______

The principal quantum number is related to the distance of an orbital from the nucleus, whereas the subshells are related to orbital shape.

The representative elements (also called the main group elements) are the elements in Groups______ and Groups _______ on the periodic table. These elements are so called because they are the __________elements in nature and provide a wide representation of the elemental and chemical characteristics found in natural systems.

The representative elements (also called the main group elements) are the elements in Groups 1-2 and Groups 13-18 on the periodic table. These elements are so called because they are the most abundant elements in nature and provide a wide representation of the elemental and chemical characteristics found in natural systems.

The representative elements (main group elements) are the elements in Groups _____ (1A-2A) and Groups _______ (3A-8A) that are contained in the _____-block and the ____-block, respectively, of the periodic table

The representative elements (main group elements) are the elements in Groups 1-2 (1A-2A) and Groups 13-18 (3A-8A) that are contained in the s-block and the p-block, respectively, of the periodic table

The second ionization energy is the energy required to remove the ______ of two electrons from an atom. The second ionization energy tends to ______ across a period and to ______ down a group; however, ionizations involving core electrons are ______ energy than those involving valence electrons.

The second ionization energy is the energy required to remove the second of two electrons from an atom. The second ionization energy tends to increase across a period and to decrease down a group; however, ionizations involving core electrons are higher energy than those involving valence electrons.

When a reaction occurs under conditions such that it is reversible (eg, high temperatures), it is said to be under ________ control. Under these conditions, all products form readily and the most _______ product will be favored (ie, the most negative ΔG), as it is least likely to undergo the reverse reaction.

When a reaction occurs under conditions such that it is reversible (eg, high temperatures), it is said to be under thermodynamic control. Under these conditions, all products form readily and the most stable product will be favored (ie, the most negative ΔG), as it is least likely to undergo the reverse reaction.

To identify the geometry of a molecule, first determine the molecule's electron group ______ by counting the number of ________ domains, which includes _____ electron pairs and _____ bonds. Next, determine how many of the electron domains are _____ and how many are _____ _______ If all the electron domains are from bonds, the molecule's geometry will be the same as its _____ group geometry. If lone pairs are present, the _______ geometry will be different from electron group geometry.

To identify the geometry of a molecule, first determine the molecule's electron group geometry by counting the number of electron domains, which includes lone electron pairs and sigma bonds. Next, determine how many of the electron domains are bonds and how many are lone pairs. If all the electron domains are from bonds, the molecule's geometry will be the same as its electron group geometry. If lone pairs are present, the molecule's geometry will be different from electron group geometry.

When NADH is oxidized to NAD+, it occur at the ______ and it must lose electrons. This process produces an _________ __________ as electrons spontaneously flow from anode to cathode.

When NADH is oxidized to NAD+, it occur at the anode and it must lose electrons. This process produces an electric potential as electrons spontaneously flow from anode to cathode.

When a stable anion is formed, _______ is released, which results in a ______ value for the change in energy. Therefore, elements with a more negative electron affinity more readily accept the addition of an electron. Electron affinity trends show that apart from some exceptions caused by atomic size and orbital-filling effects, values tend to become more _______ (higher affinity) moving left to right across a period and become more ________ (lower affinity) moving down a group on the periodic table.

When a stable anion is formed, energy is released, which results in a negative value for the change in energy. Therefore, elements with a more negative electron affinity more readily accept the addition of an electron. Electron affinity trends show that apart from some exceptions caused by atomic size and orbital-filling effects, values tend to become more negative (higher affinity) moving left to right across a period and become more positive (lower affinity) moving down a group on the periodic table.

When the conditions are such that a reaction is __________ (eg, low temperature), it is said to be under kinetic control, and the most favorable product is the one whose pathway has the ______activation energy. Unless the reactions have had time to complete, the _______ reaction will yield the most product.

When the conditions are such that a reaction is irreversible (eg, low temperature), it is said to be under kinetic control, and the most favorable product is the one whose pathway has the lowest activation energy. Unless the reactions have had time to complete, the fastest reaction will yield the most product.

When the product of the concentrations of ions in solution is equal to Ksp, the _______ and _______ rates are equal. Under these conditions, the solution is said to be ___________, and any increase in ion concentration will result in precipitation.

When the product of the concentrations of ions in solution is equal to Ksp, the dissolution and precipitation rates are equal. Under these conditions, the solution is said to be saturated, and any increase in ion concentration will result in precipitation.

With respect to atomic electronic configurations, the representative elements are those elements found in the _____-block and the ______-block of the periodic table. The ______-block elements have valence electrons of highest energy occupying an _______orbital whereas the _______-block elements have valence electrons of highest energy occupying a ______orbital. [An alternative numbering system for the element groups involves a number (sometimes expressed as a Roman numeral) along with a letter (A or B). Although this older numbering system is now considered obsolete, it is sometimes still used because, for the representative elements, it correlates to the number of valence electrons in each group (with the exception of helium). For example, elements in Group 3A each have three valence electrons.]

With respect to atomic electronic configurations, the representative elements are those elements found in the s-block and the p-block of the periodic table. The s-block elements have valence electrons of highest energy occupying an s orbital whereas the p-block elements have valence electrons of highest energy occupying a p orbital. [An alternative numbering system for the element groups involves a number (sometimes expressed as a Roman numeral) along with a letter (A or B). Although this older numbering system is now considered obsolete, it is sometimes still used because, for the representative elements, it correlates to the number of valence electrons in each group (with the exception of helium). For example, elements in Group 3A each have three valence electrons.]

Within a group (column), the atomic radius _______ from top to bottom because each successive atom in the group has an additional electron shell. The outer electrons are shielded from the pull of the protons by the inner electrons. The electrons experience a ______ attractive force toward the nucleus (effective nuclear charge, Zeff), so they orbit farther from the nucleus.

Within a group (column), the atomic radius increases from top to bottom because each successive atom in the group has an additional electron shell. The outer electrons are shielded from the pull of the protons by the inner electrons. The electrons experience a decreased attractive force toward the nucleus (effective nuclear charge, Zeff), so they orbit farther from the nucleus.

Within each period (row), the atomic radius gradually ________ from right to left. With each step to the right, an electron and a proton are added. The charge in the nucleus ______ with each additional proton, causing a gradual drawing in of the electron cloud. Because the number of electron shells is constant within a period, each new electron is added to the same shell and cannot effectively shield other electrons from the nucleus

Within each period (row), the atomic radius gradually increases from right to left. With each step to the right, an electron and a proton are added. The charge in the nucleus increases with each additional proton, causing a gradual drawing in of the electron cloud. Because the number of electron shells is constant within a period, each new electron is added to the same shell and cannot effectively shield other electrons from the nucleus

what would be the fastest way of finding the density of an ideal gas knowing the conditions?

density= (Pressure x MW) / ( RT)

Which of the following alkaline-earth species are diamagnetic? Ca Ca+2 Sr A.I only B.II only C.I and III only D.I, II, and III

electrons fill the shells and subshells of an atom in order of increasing energy according to Hund's rule and the Pauli exclusion principle. Unpaired electrons in the electronic configuration of an atom or ion result in paramagnetism, but a configuration without unpaired electrons results in diamagnetism.(ANS: D)

he energy of a photon is given by Ephoton=________. For a molecule or atom to transition from ground to an excited state, it must ______ a single photon with energy exactly equal to the _______ between the two states.

he energy of a photon is given by Ephoton=hc/λ. For a molecule or atom to transition from ground to an excited state, it must absorb a single photon with energy exactly equal to the energy difference between the two states.

if the strengths of the σ bond and π bond contributors are considered separately, _____ bonds are weaker than ________bonds. The _______ orbital overlap in σ bonds is ______ efficient than the side-to-side orbital overlap in _______bonds. This causes σ bonds to exist in a _____stable, ________ energy state. As a result, breaking a _____ bond requires ______ added energy than breaking a __________bond (ie, a σ bond has a _______ dissociation energy).

if the strengths of the σ bond and π bond contributors are considered separately, π bonds are weaker than σ bonds. The end-to-end orbital overlap in σ bonds is more efficient than the side-to-side orbital overlap in π bonds. This causes σ bonds to exist in a more stable, lower energy state. As a result, breaking a σ bond requires more added energy than breaking a π bond (ie, a σ bond has a greater dissociation energy).

the sign of the change in ΔS for a process determines whether the process becomes ______ or ______ thermodynamically favorable as the temperature increases. A _______ ΔS causes ΔG to increase with temperature, whereas a _______ ΔS causes ΔG to decrease with temperature.

the sign of the change in ΔS for a process determines whether the process becomes more or less thermodynamically favorable as the temperature increases. A negative ΔS causes ΔG to increase with temperature, whereas a positive ΔS causes ΔG to decrease with temperature.

two electrons in the same orbital must have spins of opposite alignment, this fact is related to the _______ _______ principle which says that no two electrons in a given atom can have the same set of quantum numbers.

two electrons in the same orbital must have spins of opposite alignment, this fact is related to the Pauli exclusion principle which says that no two electrons in a given atom can have the same set of quantum numbers.