Gen Chem

What are the strong acids using the mnemonic?

"Hi class is boring. Will I skip class over twice? No, so let me add my hydrogens and double check" 1. HI 2. HCl 3. HBr 4. HNO3 5. HClO3 6. HClO4 7. H2SO4

What are the strong bases using the mnemonic?

"Like Nathaniel Knows California Surely is Bad" Add all the OH and double the second half 1. LiOH 2. NaOH 3. KOH 4. Ca(OH)2 5. Sr(OH)2 6.Ba(OH)2

What would the Ka equation be for the ionization of HCN in water and what would the equation for the base dissociation constant Kb for the conjugate base of HCN?

**they are opposites**

Common units of pressure

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

1 Faraday is equal to what?

1 faraday equals the electric charge present in 1 mol of electrons

What kind of emission do you get for the three types of radioactive decay?

1. Alpha decay = ejection of an alpha particle 2. Beta decay = ejection of a nuclear electron or positron 3. Gamma emission = release of a high energy photon

What are the 4 assumptions from the Bohr model?

1. Electrons move around the nucleus in fixed circular orbits, which are only allowed at particular intervals from the nucleus 2. Electrons in orbits farther from the nucleus have higher energy than electrons in orbits closer to the nucleus 3. Energy is absorbed by an electron moving from a lower orbit to a higher orbit, but energy is emitted by an electron returning from a higher orbit back to a lower orbit 4. The energy that is absorbed or emitted by an electron equals the energy difference between two orbits

What are the three types of electrochemical cells?

1. Galvanic cells (voltaic) - spontaneous reaction 2. Concentration cells - house spontaneous reaction 3. Electrolytic cells - house non spontaneous reaction

What is the definition for each of the following: 1. Lewis acid 2. Lewis base 3. Bronsted-lowry acid 4. Brownsted-lowry base 5. Arrhenius Acid 6. Arrhenius base

1. Lewis acid = accepts electron pair 2. Lewis base = donates electron pair 3. bronsted Lowry acid = donates H+ 4. Bronsted Lowry base = accepts H+ 5. Arrhenius acid = donates H+ (produces H+ in solution) 6. Arrhenius base = donates OH- (produces OH- in a solution)

What is the rule for determining hybridization?

1. Look at the atom. 2. Count the number of atoms connected to it (atoms - not bonds!) 3. Count the number of lone pairs attached to it. 4. Add these two numbers together. If it's 4, your atom is sp3. If it's 3, your atom is sp2. If it's 2, your atom is sp. (If it's 1, it's probably hydrogen!)

What are the five characteristics of an ideal gas?

1. Relatively negligible molecular volume (~ 0 volume) 2. No attractive or repulsive interactions 3. Kinetic energy increases with higher temperature 4. Elastic collisions 5. Pressure produced by combined force of collisions

What are the properties of isotopes?

1. They have the SAME chemical properties (electron configuration) 2. they have DIFFERENT physical properties (number of neutrons) 3. Examples of chemical properties = bonding and reactivity 4. Examples of physical properties = density and mass

What are the 4 colligative properties?

1. Vapor pressure lowering 2. Boiling point elevation 3. Freezing point depression 4. osmotic pressure (increases)

What are the oxidation number rules

1. elements by itself or diatomic elements = 0 2. Group 1A = +1 3. Group 2A = +2 4. halogens = -1 but with oxygen its +1 5. monoatomic ion = ion charge 6. Hydrogen = +1 with nonmetals and -1 with metals 7. Oxygen = -2 but with peroxide (H202) its -1 8. Fluorine = -1

The four equations relating pH and pOH

1. pH = -log [H+] 2. pOH = -log [OH] 3. pH + pOH = 14 4. [H+] = 10^-pH

what are the equations relating pKa/pKb and Ka/Kb

1. pKa = -log (ka) 2. pKb = -log (kb) 3. pKa + pKb = pKw = 14

What is true about the Arrhenius equation?

1. the rate constant increases exponentially with increasing temperature 2. the rate constant increases exponentially with decreasing activation energy (bc of the neg sign) 3. the rate constant is greater for a catalyzed reaction than for an uncatalyzed reaction

What is the difference between the 1st, 2nd and 3rd ionization energies

1st and 2nd ionization energies remove valence electrons but the 3rd ionization energy removes a core electron. Thats why the 3rd one is much higher than the 1st two

London dispersion forces occurs btw what forces

2 molecules whose proximity to each other induces a mutual attraction via the creation of a weak, temporary dipole moment

What is the difference between a homogenous and heterogenous catalyst?

A homogenous catalyst is the in the same phase as the reactants while a heterogenous catalyst is not

How can a spark cause a reaction to occur?

A spark releases heat into the system, raising the temperature and therefore the kinetic energy of nearby molecules. These molecules are then able to react exothermically, releasing more heat into the system and providing more molecules with sufficient energy to react

The emission line spectrum of hydrogen displays four spectral lines in the visible region of the spectrum (picture on the opposite side). According to the Bohr model of the atom, which of the diagrams below represents the spectral line at 410 nm in the emission line spectrum?

According to the Bohr model, because electrons can exist only in certain orbits around the nucleus (not between these orbits), emissions from the hydrogen atom are seen only at particular wavelengths as a set of emission lines (a line spectrum) instead of as a continuous spectrum of all wavelengths. Likewise, in the absorption spectrum, the same wavelengths are exclusively absorbed (seen as black lines). Because light energy is inversely proportional to the wavelength, the line emission at 410 nm (the shortest wavelength in the line spectrum) must correspond to the electron originating in the highest-energy orbit. Therefore, the energy diagram depicting the transition of an electron from n = 6→2 (the highest energy emission) is associated with the shortest spectral line wavelength (410 nm)

Brownsted-Lowry Acid/Base solutions turn litmus paper into what color?

Acidic solutions (pH<7) turn litmus paper red Basic solution (pH>7) turn litmus paper blue

Where is the site of oxidation and reduction?

Anode = always the site of oxidation (it attracts anions) Cathode = always the site of reduction (it attracts cations) RED CAT = reduction at the cathode AN OX = oxidation at the anode

In an aqueous solution of 1 × 10−3 M HCN (Ka ≈ 1 × 10−9), HCN can best be described as a: A.weak acid, because [H+] < 1 × 10−3 M. B.strong acid, because [H+] = 1 × 10−6 M. C.weak base, because [H+] < 1 × 10−7 M. D.strong base, because [H+] ≈ 1 × 10−3 M

Ans A

The overall reaction for the electrolysis of molten sodium chloride, 2 NaCl(l) −→ 2 Na(l)+Cl2(g) can be expressed as two separate, simultaneous redox processes (Reactions 1 and 2): 2 Cl− → Cl2(g)+ 2 e− Reaction 1 2 Na+ + 2e− → 2 Na(l) Reaction 2 What is the amount of electric charge required to produce 0.80 mol of Na(l) during the electrolysis? A.0.8 faradays B.1.6 faradays C.2.4 faradays D.3.2 faradays

Ans A

Which gas would occupy more volume at a constant temperature and pressure, 1.5 g of N2 gas or 1.5 g of O2 gas? A.N2 because there are more moles of N2. B.O2 because its molecules are larger. C.Neither gas occupies any volume. D.Both gases occupy equal volumes.

Ans A Because the masses of both N2 and O2 are equal (1.5 g each), the gas with the lower molar mass has more molecules. Using the periodic table, the molar mass of N2 is calculated to be 28 g/mol, and the molar mass of O2 is 32 g/mol. Therefore, the N2 gas has more moles and occupies a larger volume.

An unknown metal M forms an ionic hydroxide with the formula M(OH)2 that exhibits the equilibrium: M(OH)2(s)⇄M2+(aq)+2 OH−(aq) in a saturated aqueous solution. If the solution pH is 10, the solubility product constant Ksp of the compound is: A.5.0 × 10−31 B.5.0 × 10−13 C.1.0 × 10−12 D.1.0 × 10−8

Ans B

How many moles of electrons will be detected by the glucose meter if 160 μg of [Fe(CN)6]3− (molar mass 211.9 g/mol) react in a test strip during a measurement and each [Fe(CN)6]3− ion reacts only once? A.0.38 μmol B.0.76 μmol C.1.32 μmol D.1.51 μmol 2umol [Fe(CN)6]3− = 2 umol electron

Ans B

Phosphorus-32 is a radioactive beta-emitter used in the treatment of polycythemia vera (excess red blood cells). The radioactive decay profile for the number of 32P atoms in a 2.0-mL sample was plotted, as shown below. (opposite side) Based on the graph, what is the concentration of 32P in the sample after 1.5 half-lives have passed? A.1.2 M B.1.6 M C.2.3 M D.3.2 M

Ans B

The density of ethanol varies slightly with temperature, as shown in the table below. Based on this data, how many molecules of ethanol are contained in 30 mL of ethanol at 8 °C? (Note: The molar mass of ethanol is 46.08 g/mol.) (8 °C = .800g/mL) A.8.6 × 10^−25 molecules B.3.1 × 10^23 molecules C.4.9 × 10^23 molecules D.6.7 × 10^26 molecules

Ans B

The mean serum urate concentration (from uric acid) in a sample of urine was measured to be 64 mg/L. If a 2.0 mL aliquot of the urine sample is analyzed, what is the total mass of the serum urate present in the aliquot? A.3.2 × 10−5 g B.1.3 × 10−4 g C.3.2 × 10−2 g D.1.3 × 10−1 g

Ans B

What is the mass percent of alcohol in a solution containing 62 mL of ethyl alcohol mixed into 200 mL of water? (Note: Density of ethyl alcohol = 0.8 g/mL; density of water = 1 g/mL.) A.16% B.20% C.25% D.31%

Ans B

What is the molar concentration of hydroxide in the duodenum (pH 6.0), where neutralization of the gastric acid leaving the stomach begins to take place? A.1.0 × 10−14 M B.1.0 × 10−8 M C.1.0 × 10−7 M D.1.0 × 10−6 M

Ans B

If a naturally occurring sample of an unidentified element is found to contain three isotopes (A, B, and C) and consists of 90.5% isotope A (mass number 20), 0.3% isotope B (mass number 21), and 9.3% isotope C (mass number 22), the atomic weight of the element measured from the sample will be: A.greater than 21 amu. B.less than 21 amu. C.equal to 21 amu. D.unrelated to the amount of isotope B

Ans B Because a naturally occurring sample of an element contains a mixture of isotopes, the atomic mass of a single isotope cannot be used in chemical calculations that involve bulk, macroscale samples. Instead, the atomic weight(more correctly called the relative atomic mass) is used, which accounts for the natural abundance of isotopes by taking a weighted contribution of the mass of each isotope found in the sample. It is these weighted averages that are listed as the atomic weights on the periodic table.

What happens to the pOH of the gastric acid entering the duodenum (pH 6.0) as a result of the introduction of bicarbonate ions from incoming pancreatic secretions? A.The pOH increases as [OH−] increases. B.The pOH decreases as [OH−] increases. C.The pOH increases as [OH−] decreases. D.The pOH decreases as [OH−] decreases

Ans B The [H+] decreases as bicarbonate consumes the available H+ from the gastric acid, and the relative [OH−] increases. As a result, the duodenum (pH 6.0) is less acidic than the upper stomach (pH = 1.0). Therefore, going from the highly acidic stomach to the less acidic duodenum gives a higher pH and a lower pOH, meaning [H+] decreases and [OH−] increases.

For a concentration cell that has a potential of 0.089 V and utilizes Ni2+ solutions at the anode and the cathode, which of the following statements correctly describes the molar cell concentrations [Ni2+]anode and [Ni2+]cathode and the direction of electron flow within the cell? A.[Ni2+] is greater at the anode; electrons flow from cathode to anode B.[Ni2+] is greater at the cathode; electrons flow from anode to cathode C.[Ni2+] is greater at the anode; electrons flow from anode to cathode D.[Ni2+] is greater at the cathode; electrons flow from cathode to anode equation on the opposite side

Ans B has to be greater at the cathode bc the cathode is the denominator so the [X]anode/[Y]cathode is going to be less than 1, and the logarithmic term of the Nernst equation would be negative, causing the final value of E to be positive. Electrons always travels from anode to cathode (A to C)

The figure below shows the titration curve for an acid titrated with aqueous sodium hydroxide. When titrated in solution, which of the following salts would be most likely to produce a similar titration curve? A.(NH4)3PO4 B.KH2PO4 C.Na2HPO4 D.K3PO4 Figure opposite side

Ans B Looking at the graph, you can tell that there are 2 equivalence points. So, in the answer choices look for the one that has 2 hydrogens bc thats what will contribute to the equivalence point. A - 3 NH4 so you will have 3 equivalence points B - 2 H so 2 equivalence point C - 1 H so one equivalence point D - no H so no equivalence point

If the hydroxide concentration in common duct bile is 1 × 10−6 M, what is the pH of the bile? A.6 B.7 C.8 D.14

Ans C

What are the formal charges of the oxygen atoms in the acetate ion of the Cu(C2H3O2)2 used during the reaction if the effects from resonance are excluded? A.0 and 0 B.−2 and 0 C.0 and −1 D.−1 and −1

Ans C

Magnesium corrodes quickly in the body because Mg2+ combines with anions other than OH− to form soluble salts. Based on the solubility data given in Table 1, which of the following salts, if present, will cause the magnesium implant to corrode most quickly? A.Ca3(PO4)2 B.Ca(OH)2 C.NaCl D.NaF Table opposite side

Ans C Metals such as magnesium, in the presence of anions with which they form soluble salts, will corrode more quicklythan they will in pure water. Based on the anions in the answer choices, the possible magnesium salts are MgF2, Mg3(PO4)2, Mg(OH)2, and MgCl2. Solubility tables provide information on the relative solubilities of various combinations of cations and anions. According to Table 1, MgCl2 is substantially more soluble than magnesium with any other available anion. Therefore, magnesium will corrode much more readily in the presence of chloride anions, provided by NaCl, than it will in the presence of any other anion. In fact, the NaCl present in blood plasma is a major factor contributing to the high corrosion rate of magnesium implants in the body.

If the ETC is a spontaneous process, which of the following MUST be true about the redox reactions within each of the four complexes? A.The electron-carrying molecules in the ETC have E0′ values greater than that of oxygen. B.The overall free energy (ΔG°′) of the ETC is positive. C.The E0′ values increase as electrons are passed from one carrier to the next D.The redox reactions in complex IV are faster than the reactions in complex I.

Ans C 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

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

Ans C degree celcius + 273 kelvin = Kelvin

What is the net charge of L-phosphotyrosine when placed in an aqueous solution at physiological pH 7.4? (Note: Assume that the pKa values of the phosphoryl group are 2.2 and 7.2.) A.0 B.−1 C.−2 D.−3 Structure opposite side

Ans C.

An 84-mg sample of a compound is found to contain 36 mg of carbon, 3 mg of hydrogen, 21 mg of nitrogen, and 24 mg of oxygen. If the compound has a molecular weight of 112 g/mol, what is its molecular formula? A.C2H2NO B.C4H6N3O C.C5H6NO2 D.C4H4N2O2

Ans D

Blood gas analysis results are listed below. From the data, determine the HCO3− concentration in the blood sample resulting from the decomposition of carbonic acid. pH - 7.35 PaCO2 - 40 mm Hg PaO2 -90 mm Hg A.0.12 mEq/L B.1.2 mEq/L C.2.4 mEq/L D.12.0 mEq/L

Ans D

Suppose that Experiment 2 is repeated using chloride salts of the Group 1 metals. Compared with the concentration of Cl− in the 10 mM Mg2+ solution, the concentration of Cl− in the 5 mM Na+ solution would be: A.higher B.the same C.2 times lower D.4 times lower

Ans D

What is the approximate molar concentration of Na+ ions in a solution prepared by dissolving 8.2 g of Na3PO4 (MM = 163.94 g/mol) into 250 mL of water? A.6.0 × 10−4 M B.3.3 × 10−2 M C.2.0 × 10−1 M D.6.0 × 10−1 M

Ans D

When comparing single, double, and triple covalent bonds formed between two atoms X and Y, decreasing the number of π bonds between the atoms will: A. decrease the overall bond dissociation energy and bond strength. B. increase the bond length. C. decrease the bond rigidity (allow more bond rotation). D. A,B,C

Ans D

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

Ans D

Sebacic acid (HOOC−(CH2)8−COOH) is a naturally occurring dicarboxylic acid that is also found as a normal urinary acid. Which procedure should be followed to determine the amount of sebacic acid present in 200 mg of an unknown sample composed primarily of sebacic acid and a small percentage of neutral impurities? A.Dissolve the sample in 0.1 M acid, then titrate the solution with 0.1 M base and an indicator. B.Dissolve the sample in 0.1 M acid, then titrate the solution with 0.1 M acid and an indicator. C.Dissolve the sample in 0.1 M base, then titrate the solution with 0.1 M base and an indicator. D.Dissolve the sample in 0.1 M base, then titrate the solution with 0.1 M acid and an indicator.

Ans D After dissolving the acid with a base, the solution will become basic and so to titrate you will need an acid

Consider the equilibrium that exists for a saturated aqueous solution of PbCl2. PbCl2(s)⇄Pb2+(aq)+2 Cl−(aq) Which expression gives the solubility product constant Ksp for PbCl2 if the [Pb2+] = n mol/L? A.n2 B.2n2 C.n3 D.4n3

Ans D mol to mol conversion is the important aspect here

What is the pattern with bond order, energy and bond length

As bond order increases (single->double->triple), bond length decreases, bond strength increases and bond energy increases

How many vibrational modes of the coordinate bonds from each isomer of copper(II) glycinate are observable by far-IR spectroscopic analysis? (Note: Exclude skeletal vibrational modes unrelated to the coordinate bonds.) A.Four modes in both the trans isomer and the cis isomer B.Two modes in the trans isomer and 4 modes in the cis isomer C.Four modes in the trans isomer and 2 modes in the cis isomer D.Three modes in the trans isomer and 5 modes in the cis isomer

Comparing the number of vibration modes for each isomer to their respective far-IR spectra, the cis isomer is seen to display four peaks (in addition to the skeletal vibration peak at 385 cm−1 - the skeletal peak is said in the passage and that's how you know); however, the trans isomer displays only two peaks along with the skeletal vibration peak. This indicates that two of the four vibrational modes of the coordinate bonds in the trans isomer are not IR-active.

According to Avogadro's law, when the # of moles of gas increases, the volume increases in direct proportion. If the mass for two gases are given, how do you find which one has a larger volume?

Convert the mass of both gases into moles and whichever has the largest amount of moles will have the largest volume

Which direction do electrons and current flow?

Electrons flow = Anode to Cathode (A comes before C) Current flows = (opposite of electron flow) Cathode to Anode

Where do electrons flow as opposed to ions?

Electrons flow in wires and electrodes while ions flow in the electrolyte solution, thus creating a completed circuit

What is the electromotive force (EMF) and Gibbs free energy for galvanic, electrolytic and concentration cells?

Emf and change in free energy always have opposite signs

For endothermic and exothermic reactions heat is considered what?

Endothermic = heat is one of the reactants Exothermic = heat is one of the products

What is coordination number

Equal to the number of coordinate covalent bonds

What is Faradays equation

Faraday's constant = coulombs of charge per mol of electron = total charge over total mols of electrons F = Q/n

What is the titration curve for H2CO3?

For H2CO3 (polyprotic acid): pKa1: [H2CO3] = [HCO3-] Equivalence point 1: almost everything is HCO3- pKa2: [HCO3-] = [CO32-] Equivalence point 2: almost everything is CO32- At each pka [acidic species] = [conjugate base of the acidic species]

What is the equation to determine the standard potential for an oxidation-reduction pair for an electrochemical cell?

For electrolytic cell, this is neg and for galvanic its positive

What are two formulas for formal charge?

Formal charge = Should - has Oxidation state = valence - nonbonding electrons - bonding electrons

what is the charge for anode and cathode in the galvanic and electrolytic cells?

Galvanic --> Anode = NEG, Cathode = POS Electrolytic cell --> Anode = POS, Cathode = NEG

Galvanic vs electrolytic cell image

Galvanic cell contains a voltmeter electrolytic cell contains a battery

What is the formula for carbonic acid

H2CO3

For an endothermic reaction, if you increase the heat what will happen to the Ksp (solubility product constant)?

Heat is one of the reactants, so according to Le-Chatelier's principle, increasing one of the reactants will drive the reaction towards the products. If the products increases, then the Ksp will also increase (based on the equation for ksp)

Example of how to draw out paramagnetic vs diamagnetic

Here, even tho Ca2+ is not filled, it counts as diamagnetic because there are no unpaired electrons

Hydrogen atoms covalently bond with what to exhibit hydrogen bonding?

Hydrogen atoms covalently bonded with nitrogen, oxygen, or fluorine atoms form polar bonds that yield dipoles, which exhibit significant noncovalent dipole-dipole attractions known as hydrogen bonding

What is the acid strength of hydrogen halides and why?

H−I > H−Br > H−Cl >> H−F

How do you find the electrons is a neutral atom vs a charged atom

In a neutral atom, the number of electrons is the same as the number of protons (atomic number) For charged atoms, the electrons can be found by substracting the charge from the atomic #

What is the periodic trend for ionic radii? (different from atomic radius)

Ionic radii decrease in size across a period and increase down a group on the periodic table. (same trend as atomic radius) notice how it goes cations and then resets and then goes anions

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-

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. 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.

What is Gay-Lussac's Law?

Isovolumetric heating Pressure and Temperature are directly proportional (n and V are constant) Equations: P/T = k or P1/T1 = P2/T2

What is a saturated solution?

It contains the maximum amount of a compound that will dissolve in a given volume of solvent under the given conditions

What is the AHED mnemonic explain

It explains the things that happens when an electron goes from a lower energy level (closer to the nucleus) to a higher energy level (farther away from the nucleus) Absorb light Higher potential Excited Distant from nucleus

If an atom has a low ionization energy, what is its reactivity?

It would have a high reactivity High ionization energy = low reactivity

What is the acid dissociation constant

Ka=[H+][A−]/[HA]

Difference between kinetic and thermodynamic products

Kinetic product - higher in free energy than thermodynamic products and can form at lower temperatures. "Fast" products because they can form more quickly under such conditions Thermodynamic product - lower in free energy than kinetic products, more stable. Slower but more spontaneous (more neg ΔG°)

How does the Ka or Kb quantify acid/base strength

Larger Ka or Larger Kb = stronger acid or base respectively

What is the energy density of Lead-Acid and Ni-Cd?

Lead Acid has a low energy density and Ni-Cd has a higher energy density then lead acid

What are the angles for linear, trigonal-planar, tetrahedral and bent tetrahedral (water) geometry?

Linear = 180 trigonal-planar = 120 tetrahedral = 109.5 bend tetrahedral = 104.5

what is the weakest type of van Der Waals?

London dispersion forces

Which groups in the periodic table have high, low and intermediate electrical conductivity?

Metals = most conductive Metalloids = low, intermediate Nonmetals = least conductive

Buffers consist of what kind of mixtures?

Mixture of either a weak acid and a salt of its conjugate base or a weak base and a salt of its conjugate acid

How are neutral, acidic and basic salts formed?

Neutral salts are formed from a strong acid reacting with a strong base give a neutral solutions (pH = 7) Acidic salts formed from a strong acid reacting with a weak base give acidic solutions (pH < 7) Basic salts formed from a weak acid reacting with a strong base give basic solutions (pH > 7)

Can impurities that undergo the same oxidation reduction behavior as the analyte be distinguished from the analyte?

No, and they also decrease the accuracy of the measured equivalent point in a redox titration

When you get gamma emission, do you get any changes in the number of atomic number or atomic mass?

No, you only get release of a high energy photon but no particle is emitted and the number of protons and neutrons in the nucleus remains unchanged

Rechargeable and non-rechargeable batteries work as what type of cells

Non-rechargeable = galvanic cells Rechargeable = both electrolytic (charging) and galvanic (discharging)

what is the mnemonic that tells you what is oxidation and reduction in terms of electrons

OIL RIG - Oxidation is losing electrons; Reduction is Gaining electrons Oxidation is an increase in charge, Reduction is a decrease in charge

What is the difference between paramagnetic vs diamagnetic

Paramagnetic = unpaired electrons Diamagnetic = no unpaired electrons

If, Q < Keq Q = keq Q > keq what happens to ΔG°?

Q < keq --> ΔG° < 0, reaction proceeds towards products Q = keq --> ΔG° = 0, equilibrium Q > keq --> ΔG° > 0, reaction proceeds back to reactants

How can you combine Faradays constant and current?

Q = IT and Q = nF so: IT=nF Current x time = mols of electrons x Faraday's constant

Oxidation and reduction involves the formation of bonds to what?

Reduction often involves the formation of bonds to hydrogen Oxidation often involves the formation of bonds to oxygen

What is the reduction potential vs oxidation potential?

Reduction potential = potential of the reduction half reaction --> ex: Cu2+ + 2e- → Cu Oxidation potential = potential of the oxidation half reaction --> ex: 2Ag → 2Ag+ + 2e- they are opposite of each other in terms of signs. And if one is high the other will be low.

What is the number of electron sub shell number for s, p , d and f

S = 1 P = 3 D = 5 F = 7

What is Avogadro's principle

Says that as the number of mols of gas increases, the volume increases in direct proportion Equation: n/V = k or n1/V1 = n2/V2 (T and P are constant

What does the law of mass action state?

States that an equilibrium constant Keq can be expressed as a ratio of the molar concentrations of the products over the reactants, each raised to the power of its respective balanced reaction coefficient. But for a reaction in which one of the reactants is also the solvent, the solvent species is omitted from the keq expression

How much do strong acids vs weak acids ionize in a solution?

Strong acids ionize essentially 100% in aq solutions, resulting in a large acid dissociation constant (Ka > 1), whereas weak acids ionize only to a small extent, resulting in a small acid dissociation constant (Ka < 1)

what is the only thing that can alter Keq?

TEMPERATURE

what equation describes the relationship between the rate constant and the temperature and activation energy of a reaction?

The Arrhenius equation k = rate constant A = frequency factor (measure of how often certain molecules in a rxn collide; high concentration n= more collisions) Ea = activation energy R = gas constant = 8.314 J/molK T = temp in kelvin

Which group in the periodic table is very reactive and why?

The alkali metals (group 1) are very reactive because of their low ionization energy, large atomic radius and small electronegativity Cs is the most reactive metal

From a graph how can you tell if a compound is a kinetic or thermodynamic product?

The compound with the lowest energy transition state (lowest energy barrier for formation) forms fastest, making it the kinetic product. The compound with the most stable (lowest energy) structure is the thermodynamic product, but bc it has a higher energy transition state (higher energy barrier for formation), it forms more slowly

The fact that water has a high surface tension is not relevant to what fact?

The fact that water can act as a solvent

What is the reactivity of an atom depending on the ionization energy

The higher the ionization energy, the least reactive the atom ionization energy increases down to up and left to right across the periodic table

The chemical structures of sulfur compounds H2S, SF6, S2Cl2, and S4N4 each contain only single (sigma) bonds. The compound that contains the longest bond between sulfur and an atom of another element is: A.H2S B.SF6 C.S2Cl2 D.S4N4

The length of the sigma bond can be found by the atomic radius trend on the periodic table In this question, the given compounds all have σ bonds to a sulfur atom. As a result, the longest bond between sulfur and another element will be formed with the element that has the largest atomic radius. Because Cl has a larger atomic radius than H, N, or F, the S-Cl bond in S2Cl2 will the longest bond with sulfur among the given compounds.

Within coordination complexes. what acts as a lewis base and what acts as a Lewis acid?

The ligand works as a Lewis base and the metal center acts as a Lewis acid

What is the equation to find the effective nuclear charge (Zeff)?

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

when small amount of strong acid or base are added to a buffer solution, what happens to the solution pH?

The solution pH changes only slightly Adding strong acid causes the pH to decrease slightly whereas adding a strong base causes the pH to increase slightly

What is ohms law?

V=IR voltage = current x resistance

Why is hb red when it binds to o2?

When heme binds to o2, the nature of the oxygen ligand changes the energy of iron's d orbitals. This energy change causes heme to absorb blue-green and reflect red light

In a solution, when do you see the precipitation of products?

When the concentrations of the products multiplied together exceeds the solubility product constant (Ksp) bc that means the solubility limit of the solution has been exceeded and the solution will not accept any more ions. This will cause any ions in excess of the Ksp to come out of solution as a precipitate

Exact density of a substance varies slight with what?

With temperature

If the solubility product constant Ksp for NaC9H7O4 is estimated to be 34.9, what is the approximate acetylsalicylate ion concentration in the saturated NaC9H7O4 solution used for the reaction? A.2.95 M B.5.91 M C.17.4 M D.34.9 M

[C9H7O4]=(sqrt)Ksp=(sqrt)34.9 [C9H7O4]=5.91M Here, it is unnecessary to perform a rigorous manual calculation of the square root of 34.9. Instead, the correct answer can be identified by approximation. Because 5^2 = 25, and 6^2 = 36, the square root of 34.9 must be between 5 and 6.

How can you find an unknown half reaction when given the balanced net reaction and one of the half reactions?

an unknown half reaction can be found by adding the balanced net reaction to the INVERSE of the known half reaction

Nonmetals gain electrons to form what?

anions

When 2 g of aluminum foil is added to 500 mL of the CuCl2 solution indicated in Table 1, the following reaction takes place: 2 Al(s) + 3 CuCl2(aq) → 2 AlCl3(aq) + 3 Cu(s) The limiting reactant is: A.aluminum B.copper C.copper(II) chloride. D.aluminum chloride

ans A concentration for CuCl3 given in the passage

What volume of the solutions tested would contain 0.075 g of oxytocin monoacetate? A.0.022 mL B.0.25 mL C.23 mL D.250 mL concentration given = .3mg/ml

ans D

Hydrophilicity increases as what group increases?

as the number of polar bonds increase such as O-H, N-H, C-F etc

The length of a sigma bond can be estimated as the sum of what?

as the sum of the atomic radii of the bonded atoms bc the sigma bond is made by the end to end overlap of atomic orbitals

Whenever they ask for ions in the question, what are you supposed to use?

avogradros number 6.0x10^23

What is a decomposition reaction?

breaking down of a compound into its elemental constituents or into simpler, stable compounds usually requires the addition of energy such as heat to break the bonds of the original compound

How do buffer solution resist changes in pH

by neutralizing H+ or OH- ions when small amounts of a strong acid or strong base are added

The freezing point of a substance is determined by what?

by the strength and extent of intermolecular forces acting between molecules stronger intermolecular forces, increasing melting temperature

What is the equation to find the concentration ratio?

concentration ratio = [stock solution]/[standard solution] The ratio of the concentrations can be used to determine how much larger or smaller the concentration of one solution is compared to the other

A buffered solution consists of what?

consists of a weak acid and a salt of its conjugate base or a weak base and its conjugate acid

What is the equation for current?

coulombs of charge per second I= Q/t

What is the difference between decomposition and combustion reactions ** don't get them confused **

decomposition - is the breakdown of a molecule combustion - involves a fuel, usually a hydrocarbon and O2; commonly forms CO2 and H2O

How can you find the number of neutrons in an isotope

determined by subtracting the element's atomic number from the mass number

What is an analyte?

during a redox titration, a solution with a known concentration of an oxidizing agent is slowly added to a solution with an unknown concentration of a species to be measured

Hybridization of d2sp3 gives an electron and molecular geometry of what?

electron and molecular geometry = octahedral

Log shortcuts

factoring can be used to simplify log (memorize log(2)=0.3 & log(3)=0.48): log(0.33) = log(1/3) = log(1) - log(3) = 0 - 0.48 = -0.48 log(1.5) = log(3/2) = log(3) - log(2) = 0.48 - 0.3 = 0.18 log(5) = log(10/2) = log(10) - log(2) = 1 - 0.3 = 0.7 log of less than 1 will always be negative & for multiples of 10 it's just the # of decimal places: log(0.1) = -1; log(0.01) = -2; log(0.001) = -3 An even easier way to get approximate answers is to memorize: log(2) = 0.3 log(3) = 0.5 log(5) = 0.7 Also memorize: ln(2) = 0.69 and ln(x) = 2.3log(x)

What are coordinate bonds?

formed between 2 atoms when both of the shared electrons are donated by the same atom this is often formed between electron poor metal ions and molecules called ligands that contain one or more electron rich atoms with available lone- pair electrons

Greater solubility corresponds to what?

greater solubility corresponds to a faster corrosion rate

What is a reference electrode?

has a known electric potential and standard concentration of reacting species

Rule of thumb for hydrogen bonding

if it has oxygen, nitrogen and fluorine, it can hydrogen bond

A lead storage battery is an example of an oxidation-reduction reaction that occurs in what type of electrolyte?

in an acidic electrolyte

The rate of metal corrosion increases in the presence of what?

in the presence of anions with which the metal forms soluble salts

the overall reduction potential of a redox pair indicates what?

indicates how likely a particular compound is to gain or lose electrons more + values indicates a tendency to accept electrons more - value indicates a tendency to lose electrons

What is Charles's Law?

isobaric expansion Volume and temperature are directly proportional (n and P are constant) Equations: V/T = k or V1/T1 = V2/T2

What is Boyle's law?

isothermal compression Pressure and volume are inversely related (n and T are constant) Equations: PV=k (k is constant) or P1V1=P2V2

The bicarbonate ion can act as what

it is a base (proton acceptor) capable of neutralizing gastric acid through the formation of CO2 and H2O

what is bond dissociation energy

it is the energy required to break a bond

What is the theoretical yield?

it is the maximum amount of product that can be formed in a reaction. Its governed by the limiting reactant, which is determined by the balanced equation and the molar amounts of each reactant available

how is the rate law determined for elementary reactions?

it is written as the product of the rate constant (k) and the concentration of the reactants, in which the stoichiometric coefficient of each reactant is its exponent

What is the trend for bond dissociation energy?

it tends to increase with each additional pi bond single bond = lowest bond dissociation energy double bond = medium triple = highest bond dissociation energy

Increasing the surface area of a catalyst in a reaction will increase what?

it will increase the rate of the reaction heterogenous catalyst involve the adsorption of reactants onto the surface of the catalyst and provide higher reaction rates with increase in surface area

when will the actual yield be less or greater than the theoretical yield

it would be less when some of the product is lost in the process of conducting laboratory procedures like filtering or transferring it would be more when a product contains impurities or has not been completely dried before weighing

What is the Arrhenius equation conceptually

its the concept that the molecules that collide to react must have kinetic energy to overcome the activation energy of the reaction

Electromagnetic spectrum

know everything from this picture by heart!!!

Atoms with a large/small difference in electronegativity usually form what kind of bonds?

large difference = ionic bonds usually btw a metal and a nonmetal small difference = covalent bonds usually btw 2 nonmetals

When is an atom oxidized vs reduced

losing electron (becoming more +) = oxidized gaining electron (becoming more -) = reduced

A lower pKa is indicative of what kind of acid

low pKa = stronger acid basically acid strength increases as pKa decreases

What is electron affinity

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. Ex: oxygen in group 16 has the lowest electron affinity despite being the most electronegative in that group. The reason is bc oxygen's valence electrons experience more electron-electron repulsion than other group 6A elements

How can you tell if a metal cation is a strong or weak lewis acid?

metal cations with a smaller ionic radius and a higher positive charge are stronger Lewis acids than those with a larger ionic radius and lower charge

The pH of a buffered solution depends on what?

on the ratio of weak acid and its conjugate base

what is an elementary reaction?

one step reaction with a single transition state

A catalyst only effects what?

only effects the reaction rate but do NOT change 1. Equilibrium (Ka) 2. Enthalpy (delta H) 3. Entropy (delta S) 4. Temperature

Equations for pH and pOH

pH = -log[H+] pOH = -log[OH] pH + pOH = 14 [H+] = 10^-pH

What is the triple point in the phase diagram?

point at which all three boundary lines intersect and indicates the temperatures and pressure at which all three phases simultaneously exist in equilibrium

Free rotation is/not possible around which bonds?

possible around sigma bonds so single bonds only but not possible around pi bonds like double and triple bonds

Define colligative properties

properties that depend only on the NUMBER of solute particles

Solubility tables provide information about what?

provide information on the relative solubilities of potential salts to be formed

What are disproportionation reactions

redox reactions in which both the oxidation and the reduction occur to atoms of the same element

What are reducing/oxidizing agents?

reducing agents gives up electrons to reduce another compound but itself is oxidized Oxidizing agent receives electron from reducing agents and is the compound thats reduced reducing agent = oxidized (loss of electrons) (becomes more positive in number) oxidizing agent = reduced (gain of electrons) (becomes more negative in number)

How many groups are attached to each of the following? s sp sp2 sp3

s = one group sp = two groups sp2 = three groups sp3 = four groups

How are sigma and pi bonds made?

sigma = end to end overlap of atomic orbitals pi = side to side overlap of p orbitals

Which one is more stable, a sigma bond or a pi bond

sigma is more stable than a pi bond but a double bond or triple bond is stronger than a single bond

How many sigma and pi bonds do single, double and triple bond contain?

single = 1 sigma double = 1 sigma and 1 pi triple = 1 sigma and 2 pi bond

What does the van't Hoff plot tell us?

slope tells us about enthalpy y-intercept tells us about entropy neg slope = + enthalpy = endothermic

What is the aufbau principle

states that low energy orbitals are filled first

What is Raoult's Law?

states that the addition of solute to a pure substance lowers the freezing point and saturation vapor pressure of the resulting solution

What is the Heisenberg uncertainty principle

states that the exact position and momentum of a particle cannot be both known at the same time. The uncertainty of position and momentum is inversely proportional: the more accurately an object's position is known. the less accurately its momentum can be known and vice versa

Negative values of ΔG° indicate what?

that Keq > 1 and that the equilibrium favors product formation whereas positive values of ΔG° indicate that Keq < 1 with an equilibrium that favors the reactants.

What happens to the acidic electrolyte of a lead storage battery as it discharges?

the acidic electrolyte is diluted as the battery discharges because water is one of the products of the reaction

when a transition state is stabilized, what is lowered?

the activation energy

what is the best type of indicator to be used for titrations?

the best indicator for a titration is one that will give a color change at the pH of the equivalence point

Hydrophobicity increases as what group increases?

the number of methyl (CH3) groups increases in a compound

How do you find the overall reduction potential of a redox pair?

the overall reduction potential of a redox pair is the DIFFERENCE in standard reduction potentials of the oxidizing and reducing agents

The atomic number is composed of what?

the protons

The mass number is composed of what two things?

the protons and the neutrons

If the reaction is not elementary, what determines the rate law?

the slowest step (rate-determining step) determines the rate law for the entire reaction. This step can only be determined experimentally. If the initial step is the slowest, the rate law is determined simply from that step using the coefficients of each reactant as exponents in the rate law. However, if the slowest step is the second step, reaction intermediates play a role in the rate law.

what is the rate-determining step in the reaction involving two or more steps?

the step that must overcome the largest energy barrier (slowest step) to pass through the transition state is the rate determining step

What is the purpose of an indicator in titrations

they are used in acid base titrations to determine the endpoint of a titration A good indicator should change color close to the equivalence point, the point at which the stoichiometric amount of titrant needed to consume all of the acid or base in the solution has been added They dont precipitate in the reaction

Why are noble gases generally un-reactive?

they have a full valence shell so they have no affinity for electrons. IT would take energy to force and electron on them

what are polyphonic acids

they have more than one proton that can dissociate in water the titrations curve of a polyphonic acid will show as many plateaus and steps climbs as the number of protons in the acid. These represent the buffer regions and equivalence points in a titration, respectively

What are ionic bonds?

they involve a complete transfer of electrons from an atoms with low electronegativity to an atom with high electronegativity Transition metals can form ionic bonds

Increasing bond strength is inversely related to what?

to bond length and acidity

Metals lose electrons to form what?

to form cations

If the central atom is dsp3 what is the molecular geometry?

trigonal bipyramidal

what are dipole dipole interactions

when one atom is partially negative and one atom is partially positive like h2o

Do lone pairs count as groups?

yes!!!