exam 2 - knewton 4-10

Which of the following compounds would require dividing the bond dissociation energy in half when calculating the lattice enthalpy? NaCl CaBr2 ScF3 Ba3P2

NaCl (Since exactly 1 mol of solid Na combines with exactly 12 mol of gaseous Cl2 to form precisely 1 mol of NaCl(s), the bond dissociation energy will need to be divided in half.)

In which of the following element blocks does the atomic radius generally not tend to increase when moving down within a group? s block p block d block The atomic radius generally increases when going down a group in all of the above element blocks.

The atomic radius generally increases when going down a group in all of the above element blocks. (In every group, the atomic radius will increase as we move down the table, without exception. This is because each lower period features atoms with an additional shell, and that additional shell is farther from the nucleus.)

Deviations to the trends in first ionization energy occur because of which of the following? increase in effective nuclear charge orbital symmetry increasing atomic mass There are no deviations to this trend.

orbital symmetry (For example, oxygen has a slightly lower ionization energy than nitrogen because nitrogen would lose half-full p orbitals while oxygen would gain half-full p orbitals. The enhanced stability of this orbital symmetry is responsible for the deviation from the trend for these two elements.)

Which of the following increases with increasing energy? a. principal quantum number b. angular momentum quantum number c. both A and B d. neither A or B

c. both A and B (The principal quantum number and the angular momentum quantum number increase with increasing energy.)

The electron removed when a neutral atom loses an electron will always be an electron from the: a. 1s orbital b. lowest energy orbital c. highest energy orbital d. 3d orbital

c. highest energy orbital The highest energy electron is removed, which will be in the highest energy orbital which would be the valence electrons.

Which of the following has the last electron added into the f orbital? a. main group elements b. transition elements c. inner transition elements d. all of the above

c. inner transition elements (Inner transition elements are metallic elements in which the last electron added occupies an f orbital. The valence shells of the inner transition elements consist of the (n - 2)f, the (n - 1)d, and the ns subshells.)

Sublimation energy is the energy required to .... This process requires an __________ of energy, and thus has a positive value.

cause a change of phase from solid to gas, bypassing the liquid phase. input

Most exceptions to the trend of decreasing radius moving to the right within a period occur in the __________. s block p block d block There are no exceptions to this trend.

d block

Which would be an invalid listing within an electron configuration? a. 6s1 b. 4f13 c. 4p5 d. 2d5

d. 2d5 There are no 2d orbitals, so even though 5 is an acceptable number for d occupancy, this listing can not exist in an electron configuration. The following image shows the orbitals and the correct order that they will be filled.

Which ion is isoelectronic with krypton? a. I− b. Se− c. Br+ d. Rb+

d. Rb+ If rubidium loses its 5s electron it will lose a shell and attain krypton electron configuration.

For the purposes of determining electron configuration of ions, when electrons are added to a neutral atom, they will inhabit orbitals according to: a. the Pauli exclusion principle b. the Aufbau principle c. Hund's rule d. all of the above

d. all of the above (Adding additional electrons to neutral atom to form a negative ion follows the same principles that affect the electron configuration of a neutral atom.)

Which type of orbital has the highest energy within a shell? a. s b. p c. d d. f

d. f Within a shell, the energy of the orbital increases as the angular momentum quantum number increases, so f orbitals have the highest energy of these four.

For any series of isoelectronic particles, the radius _____________ as the atomic number (the number of protons) increases.

decreases

In computing ΔHlattice for a solid, which of the following represents the energy needed to break apart a compound? sublimation energy ionization energy dissociation energy electron affinity

dissociation energy (The energy required to break a chemical bond is known as the dissociation energy.)

The covalent radius generally increases when moving in which directions on the periodic table?

down and left (As we move down the table, shells are added and the radius increases. As we move left on the table, the radius will increase. As we move to the right on the periodic table, the radius will decrease because, as protons are added, the electromagnetic attraction increases, which increases the pull on valence electrons toward the nucleus and, therefore, decreases the radius.)

A carbon atom that displays linear geometry is likely to be participating in: one double bond and two single bonds one triple bond and one single bond precisely two single bonds none of the above

one triple bond and one single bond (If carbon has a triple bond, it will show linear geometry. This can also happen if the carbon atom has two double bonds.)

An atom that has a high electronegativity will have a ___________ attraction to the electrons in its bond and thus electrons will shift towards this atom, giving it a partial negative charge

stronger

The enthalpy of formation is the change in enthalpy accompanying .... This quantity may be positive or negative, depending on the _________ involved and how they interact.

the formation of a compound from its constituent elements in their ground states. atoms

Which parameter is typically included in the Born-Haber cycle? the heat of vaporization of the metal the heat of fusion of the metal the heat of sublimation of the metal the heat of deposition of the metal

the heat of sublimation of the metal (The metal will be solid in its elemental form, so to get it into the gas phase we will have to provide the heat of sublimation.)

The lowest point in energy on the Born-Haber cycle will always correspond to: neutral elements vaporized neutral atoms vaporized ions the ionic solid

the ionic solid (The ionic solid is certainly the form that will store the most energy because of the network of electrostatic interactions, so this will be the lowest point on the energy diagram that illustrates the Born-Haber cycle.)

How many electrons can an f subshell hold?

14

Which of the following has the highest energy level? a. 4s b. 3d c. 2p d. 3s

b. 3d (3d has the highest energy level of the choices because s<p<d<f. However, the 3d orbital is higher in energy than the 4s orbital.)

the strength of a bond between two atoms increases as the number of _____________ ___________ in the bond increases. Therefore, we conclude that triple bonds are __________ and shorter than double bonds between the same two atoms; and double bonds are stronger and shorter than single bonds between the same two atoms

electron pairs stronger

lattice nrg is ______________ proportional to the interionic distance so if interionic distance is large, the lattice nrg is __________

inversely small

Single bonds are ________________ and _________________ than triple bonds.

longer ; weaker

increasing the principal quantum number, n, increases the _____________ of the ion

radius

If two lattice structures each contain ions of 1+ and 1− charge, but the second has one half the interionic distance of the first one, what will be the ratio of their lattice energies?

1 to 2 (If the interionic distance is cut in half, the lattice energy will double as they are inversely proportional to each other)

If two lattice structures have the same interionic distance, but the first lattice contains ions of 1+ and 1− charge, while the second contains ions of 2+ and 2− charge, what will be the ratio of their lattice energies?

1 to 4 (Since each charge doubles, the lattice energy must quadruple.)

The electron affinity (EA) is the energy change for the process of adding an electron to a gaseous atom to form an anion (negative ion). Which of the following is true about the electron affinity? Electron affinity is always negative. Electron affinity is always positive. Electron affinity is always zero. The sign of the electron affinity depends on the element.

The sign of the electron affinity depends on the element. (For most elements, the process of adding an electron to a gaseous atom to form an anion (negative ion) is exothermic, which means that energy is released when the gaseous atom accepts an electron. However, for some elements, energy is required for the atom to become negatively charged and the value of their EA is positive.)

Which of the following are true about electronegativity? a. Electronegativity generally increases as you move across the periods (from left to right) on the periodic table. b. Electronegativity generally increases as you move down the groups (from top to bottom) on the periodic table. c. Electronegativity is a measure of the tendency of a bonded atom to attract electrons towards itself. d. Atoms with higher electronegativity have a stronger attraction to the electrons in their bonds. e. Electrons in a polar covalent bond are shifted towards the atom with the lower electronegativity.

a. Electronegativity generally increases as you move across the periods (from left to right) on the periodic table. c. Electronegativity is a measure of the tendency of a bonded atom to attract electrons towards itself. d. Atoms with higher electronegativity have a stronger attraction to the electrons in their bonds.

Orbitals that have the same energy are called: a. degenerate b. equivalent c. identical d. overlapping

a. degenerate Degenerate is the word we use to refer to orbitals that have identical energy, such as the orbitals inhabiting the same subshell.

Which of the following have the last electron added in an s or p orbital? a. main group elements b. transition elements c. inner transition elements d. all of the above

a. main group elements The main group elements have the last electron added in an s or p orbital. The transition metals and inner transition metals have the last electron added in a d or f orbital, respectively.

The 5p orbitals fill immediately after the 4d orbitals and immediately before the 6s based on: (select all that apply) a. observed experimental results b. theoretical calculations c. a hypothetical idea d. None of the above

a. observed experimental results b. theoretical calculations (The 5p orbitals fill immediately after the 4d orbitals and immediately before the 6s based on observed experimental results, and has been supported by theoretical calculations.)

Each row on the periodic table corresponds to which quantum number for s and p orbitals? a. principal quantum number b. angular momentum quantum number c. spin quantum number d. magnetic quantum number

a. principal quantum number

If we say 2p6, the 2 corresponds to: a. the energy level b. the number of orbitals that exist of that type c. the number of electrons in those orbitals d. the magnetic quantum number

a. the energy level The 2 is the n value for those orbitals, which tells us the energy level of the electrons in that subshell. The 6 tells us how many electrons are in that orbital.

the magnitude of a bond dipole moment depends on... the magnitude of the partial charges the distance between the charges the electronegativity difference all of the above

all of the above

Which of the following energy trends is NOT correct? a. s<p<d<f b. 6s<6p<6d<5f c. 4p<5s<4d<5p d. 4s<3d<4p<5s

b. 6s<6p<6d<5f Instead of 6s<6p<6d<5f, the orbitals following the 6s orbital in energy are as follows: 6s<4f<5d<6p.

Which of the following is a rule indicated by the Aufbau principle? a. Electrons fill subshells in order of principle quantum number first, and then by subshell (s before p before d...) b. Electrons are placed in the lowest energy subshell that is not fully occupied. c. One electron is placed in each subshell until the electron configuration accounts for all electrons. d. All of the above

b. Electrons are placed in the lowest energy subshell that is not fully occupied. (The Aufbau principle indicates that electrons are placed in the lowest energy subshell that is not already fully occupied. This order is illustrated by the image below. Different subshells have different capacities and each subshell will be filled before moving on to the next subshell. The s subshells hold 2 electrons. The p subshells hold 6 electrons. The d subshells hold 10 electrons. The f subshells hold 14 electrons.)

The Aufbau principle states that: a. You must place one electron in each orbital in a subshell before doubling up. b. Orbitals will be filled in order of increasing energy, which is generally in order of increasing principal quantum number. c. No two electrons in an atom can have the same set of quantum numbers. d. None of the above

b. Orbitals will be filled in order of increasing energy, which is generally in order of increasing principal quantum number. (It is the Aufbau principle that outlines the precise order in which orbitals will be filled when an atom houses its electrons. The Pauli Exclusion Principal states that no two sets of quantum numbers can be the same. Hund's Rule states that you must place one electron in each orbital in a subshell before doubling up)

The order in which orbitals are listed on an orbital diagram follows: a. Hund's rule b. the Aufbau principle c. the Pauli exclusion principle d. the Heisenberg uncertainty principle

b. the Aufbau principle (Orbitals are filled according to Hund's rule and they contain electrons possessing quantum numbers dictated by the Pauli exclusion principle, but the order in which they are listed follows the Aufbau principle.)

What will be the molecular structure surrounding a nitrogen atom in a molecule that has a double bond, a single bond, and a lone pair?

bent

Dissociation energy is the energy required to ..... The dissociation of a compound is always an _______________ process; therefore, the change in energy is always positive

break apart a compound. endothermic

The Born-Haber cycle is an application of Hess's law that ... The Born-Haber cycle is essentially Hess's Law applied to an _____________ ____________: it involves the sum of a series of thermodynamic quantities.

breaks down the formation of an ionic solid into a series of individual steps. ionic solid

The orbitals that are next highest in energy after the 4s orbital are the: a. 5s b. 4p c. 3d d. 4d

c. 3d Somewhat against intuition, the 3d orbitals are next in terms of energy following the 4s orbital.

_______states that the lowest-energy configuration for an atom with electrons within a set of degenerate orbitals has the maximum number of unpaired electrons. a. The Aufbau principle b. The Pauli Exclusion principle c. Hund's rule d. The Heisenberg Uncertainty Principle

c. Hund's rule Hund's rule states that the lowest-energy configuration for an atom with electrons within a set of degenerate orbitals has the maximum number of unpaired electrons.

Which of the following statements about nonmetals is true? a. Nonmetals tend to gain electrons to increase their mass. b. Nonmetals tend to lose electrons to to form positive ions. c. Nonmetals tend to gain electrons to obtain a noble gas electron configuration. d. none of the above

c. Nonmetals tend to gain electrons to obtain a noble gas electron configuration. A nonmetal will tend to gain a number of electrons that will give it the electron configuration of the nearest noble gas, meaning a full valence shell, which is a stabilizing characteristic.

Electrons in orbitals that experience shielding: a. are less stabilized b. have higher energy c. both A and B d. neither A or B

c. both A and B (Electrons in orbitals that experience shielding are less stabilized and have higher energy.)

The least polar bonds are formed between elements with the _____________ difference in their electonegativities.

smallest

Electron Affinity is the ... Usually, energy will be _____________ in this process (consequently, electron affinity is usually a negative energy change)

energy change associated with the addition of an electron to a neutral atom or an ion. released

If the electron affinity for an element is negative, this means that energy is released when an atom gains an electron. energy is absorbed when an atom gains an electron. energy is released when an atom loses an electron. energy is absorbed when an atom loses an electron.

energy is released when an atom gains an electron. (Electron affinity (EA) is defined as the energy change for the process of adding an electron to a gaseous atom to form an anion (negative ion). Therefore, If the electron affinity for an element is negative, this means that energy is released when an atom gains an electron. In other words, a negative value for the electron affinity means that the process of gaining an electron is exothermic, and is an energetically favorable process.)

the greater the magnitude of the charge, the __________________ the lattice nrg

greater

Elements that have similar electron configurations belong to the same:

group Elements in the same group have the same number of valence electrons, so they will be housed in orbitals in a similar way. Thus, they will have similar electron configurations.

The Born-Haber cycle is, in fact, a fairly specific thermochemical cycle; it applies specifically to ________ ___________ formed from solid metallic elements (which become the cations) and __________ _______________ elements (which become the anions).

ionic solids ; diatomic gaseous

Which of the following quantities can be calculated using the Born-Haber cycle? ionization energy dissociation energy electron affinity heat of vaporization

ionization energy dissociation energy electron affinity

Which step in the Born-Haber cycle will typically be endothermic? ionization of the metal ionization of the nonmetal lattice energy of the ionic compound heat of formation of the ionic compound

ionization of the metal (It will typically require energy to ionize the neutral metal atom to generate the cation.)

Which step in the Born-Haber cycle will typically be exothermic? sublimation of the metal ionization of the nonmetal ionization of the metal bond dissociation of the nonmetal

ionization of the nonmetal (The nonmetal will typically release energy as it becomes an anion.)

smaller ions have a smaller interionic distance which means they have a ____________________ lattice nrg

larger

Given the equation ΔHlattice = C(Z+)(Z−) / R, which of the following will result in a stronger lattice? smaller charges and closer ions smaller charges and farther ions larger charges and closer ions larger charges and farther ions

larger charges and closer ions (As the interionic distance (Ro) decreases, the denominator will decrease so the lattice energy will be higher. Similarly, if the charges (Z+ and Z−) increase, the numerator will increase so the lattice energy will be higher.)

Ionization Energy is the energy required to .... This process always requires an __________ of energy, and thus will always have a positive value.

remove an electron from a neutral atom or an ion. input

The phenomenon in which electrons that are closer to the nucleus slightly repel those that are farther out, is known as:

shielding (The phenomenon in which electrons that are closer to the nucleus slightly repel those that are farther out, is known as shielding. Shielding occurs when an electron in an atom shields another from the pull of the nucleus. This effect results in the decrease in attraction between an electron and the nucleus in any atom with more than one electron shell. Electrons in orbitals that experience shielding are less stabilized and have higher energy. This results in valence electrons being more easily removed from an atom.)

The ___________ the bond is, the stronger it is, and bond length will ____________ as we add more bonds between two atoms

shorter ; decrease

cations with larger charges are __________ than isoelectronic cations with smaller charges

smaller

The electron affinity trend is: the same as the ionization energy trend and the atomic radius trend the same as the ionization energy trend but opposite the atomic radius trend the same as the atomic radius trend but opposite the ionization energy trend the opposite of the ionization energy trend and atomic radius trend

the same as the ionization energy trend but opposite the atomic radius trend (The higher the ionization energy, the more difficult it is to lose an electron, and therefore usually the easiest it is to add an electron, so the ionization energy and electron affinity trends are parallel. These trends are both opposite the atomic radius trend, as a larger radius means lower ionization energy and electron affinity.)

Generally, on the periodic table, ionization energy increases __________.

up and right Atomic radius and ionization energy follow opposite trends. Atomic radius increases down and left, while ionization energy increases up and right. As we move to the right on the periodic table, we add protons, which contracts the radius and holds electrons more tightly so they are harder to remove.

The highest point in energy on the Born-Haber cycle will always correspond to: vaporized neutral metals and nonmetals vaporized neutral metals and ionized nonmetals vaporized ionized metals and neutral nonmetals vaporized and ionized metals and nonmetals

vaporized ionized metals and neutral nonmetals (Vaporization is endothermic, ionization of the metal is endothermic, but ionization of the nonmetal is exothermic. The highest point on the energy diagram will occur after vaporization and ionization of the metal, but prior to ionization of the nonmetal.)