Question 1

When the distance between ions is very small,

Accepted Answer

A)   the electrostatic force becomes very small.
B)   the resultant force is the electrostatic force.
C)   there is a strong quantum mechanical repulsion.
D)   the resultant force is gravitational.
E)   None of these is correct. C

Question 2

When a NaCl molecule is formed from neutral Na and Cl atoms,

Accepted Answer

A)   a net input of energy is required.
B)   there is no net output of energy.
C)   a net output of energy is obtained.
D)   the molecule forms a covalent bond.
E)   None of the above is correct. C

Question 3

The _______ bond is based on the sharing of each valence electron by many atoms.

Accepted Answer

A)   ionic
B)   covalent
C)   van der Waals
D)   hydrogen
E)   metallic E

Question 4

The bonding of the HF molecule is approximately 43.6% ionic. If its measured electric dipole moment is 6.40 * 10-30 C · m, its equilibrium separation must be

Accepted Answer

A)   0.0416 nm
B)   0.132 nm
C)   0.0625 nm
D)   0.0917 nm
E)   0.0224 nm

Question 5

The symmetric wave function $\Psi$ for two identical, widely separated, finite square wells is best represented by which of the graphs?

Accepted Answer

A)   1
B)   2
C)   3
D)   4
E)   All of these are correct.

Question 6

The energy of a diatomic molecule can best be understood in terms of

Accepted Answer

A)   electronic motion.
B)   vibrational motion.
C)   rotational motion.
D)   electronic and vibrational motions.
E)   electronic, vibrational, and rotational motions.

Question 7

In the absorption spectrum of the diatomic molecule HCl the central frequency is at
8)67 *1013 Hz, while the absorption peaks on either side are separated by 5.9 *1011 Hz. What is the energy of the lowest vibrational state?

Accepted Answer

A)   0.18 eV
B)   0.27 eV
C)   0.36 eV
D)   2.4 meV
E)   1.2 meV

Question 8

The effective force constant of the CO molecule is 1.86 kN/m. With 12 u for the mass of the carbon atom and 16 u for the mass of the oxygen atom, the frequency of vibration of the CO molecule is

Accepted Answer

A)   14.2 *1013 Hz
B)   2.47 * 1013 Hz
C)   6.42 * 1013 Hz
D)   9.76 * 1013 Hz
E)   5.93 * 1013 Hz

Question 9

The characteristic energy of rotation E0r for the O2 molecule is 1.78 *10-4 eV. Calculate the frequency of the photon absorbed for the excitation from the l = 3 to l = 4 rotational level of this diatomic molecule.

Accepted Answer

A)   4.3 * 1010 Hz
B)   3.0 *1011 Hz
C)   1.9 *1011 Hz
D)   3.4 * 1011 Hz
E)   5.6* 1011 Hz

Question 10

The two oxygen atoms in the O2 molecule are separated by 0.12 nm. What is the wavelength of the photon emitted when the O2 goes from  = 2 to  = 1 rotational states?

Accepted Answer

A)   38 mm
B)   34 mm
C)   1.1 mm
D)   1.7 mm
E)   6.9 mm

Question 11

The equilibrium separation of the atoms in a given molecule is 0.234 nm and its measured electric dipole moment is 8.76 * 10-30 C · m. What is the percentage of ionic bonding in this molecule?

Accepted Answer

A)   18%
B)   21%
C)   23%
D)   27%
E)   29%

Question 12

The separation distance of the atoms in N2 (mass = 28 u) is 0.0773 nm. The characteristic rotational energy E0r for the N2 molecule is approximately

Accepted Answer

A)   3.27* 10-4 eV
B)   2.48 * 10-4 eV
C)   4.96 * 10-4 eV
D)   1.24 * 10-4 eV
E)   1.58 *10-4 eV

Question 13

The antisymmetric wave function $\Psi$ for two identical, closely spaced, finite square wells is best represented by which of the graphs?

Accepted Answer

A)   1
B)   2
C)   3
D)   4
E)   All of these are correct.

Question 14

Gases such as CO2 and methane are considered greenhouse gases. This is because

Accepted Answer

A)   they are the most common in the atmosphere allowing them to trap more heat than the other gases.
B)   they form covalent bonds and hence can easily act as a shield for heat.
C)   the vibrational modes of the molecules are in the infrared region which imply that they readily absorb radiant heat thus preventing it from escaping into space.
D)   the gases are formed by human activity resulting in offsetting the natural balance in the gas concentrations.
E)   None of the above statements is correct.

Question 15

The figure represents two square wells that are far apart and the symmetric ($\Psi$S) and antisymmetric ($\Psi$A) electron wave functions. Which of the following statements correctly describes the probability distributions and the energies of the wave functions?

Accepted Answer

A)   The energies are the same for these two wave functions but the probability distributions are different.
B)   Neither the energies nor the probability distributions are the same for these two wave functions.
C)   The probability distributions and energies are the same for these two wave functions.
D)   The probability distributions are the same for these two wave functions but the energies are different.
E)   None of these is correct.

Question 16

The two oxygen atoms in the O2 molecule are separated by 0.12 nm. What are the values of the two lowest nonzero rotational energies of O2?

Accepted Answer

A)   9.0 * 10-5 eV and 1.8 * 10-4 eV
B)   3.6 * 10-4 eV and 11 *10-4 eV
C)   3.6 *10-4 eV and 7.2 *10-4 eV
D)   1.8 * 10-4 eV and 11*10-4 eV
E)   3.6 * 10-4 eV and 22 *10-4 eV

Question 17

In the absorption spectrum of the diatomic molecule HCl the central frequency is at
8)67 * 1013 Hz, while the absorption peaks on either side are separated by 5.9 *1011 Hz. What is the average moment of inertia of a rotating HCl molecule?

Accepted Answer

A)   1.4 *10-47 kg.m2 
B)   7.1 * 10-48 kg.m2 
C)   1.1 * 10-45 kg.m2 
D)   2.8 *10-47 kg.m2 
E)   None of these is correct.

Question 18

Which one of the following statements is true of the van der Waals bond?

Accepted Answer

A)   Any two separated molecules will be attracted to one another by electrostatic forces.
B)   The van der Waals bonds due to electrostatic forces are weaker than the ionic and covalent bonds.
C)   At high temperatures, the van der Waals forces are not strong enough to overcome the ordinary thermal agitation of atoms or molecules.
D)   At sufficiently low temperatures, the van der Waals forces will cause virtually all substances to condense into a liquid and then a solid form.
E)   All of these are correct.

Question 19

The first two non-zero rotational energies of a N2 molecule are 0.493 meV and 1.48 meV. The two nitrogen atoms are separated by

Accepted Answer

A)   0.110 nm
B)   0.192 nm
C)   0.214 nm
D)   0.096 nm
E)   0.089 nm

Question 20

The dissociation energy of an ionic compound is the negative of the potential energy of the positive-negative ion system when the ions are

Accepted Answer

A)   touching.
B)   infinitely far apart.
C)   still atoms and have not yet been ionized.
D)   at the equilibrium separation.
E)   completely dissolved in a solvent.

Exam 17: Molecules

When the distance between ions is very small,

When a NaCl molecule is formed from neutral Na and Cl atoms,

The _______ bond is based on the sharing of each valence electron by many atoms.

The bonding of the HF molecule is approximately 43.6% ionic. If its measured electric dipole moment is 6.40 * 10^-30 C · m, its equilibrium separation must be

The energy of a diatomic molecule can best be understood in terms of

In the absorption spectrum of the diatomic molecule HCl the central frequency is at 8) 67 10¹³ Hz, while the absorption peaks on either side are separated by 5.9 10¹¹ Hz. What is the energy of the lowest vibrational state?

The effective force constant of the CO molecule is 1.86 kN/m. With 12 u for the mass of the carbon atom and 16 u for the mass of the oxygen atom, the frequency of vibration of the CO molecule is

The characteristic energy of rotation E_0r for the O₂ molecule is 1.78 *10^-4 eV. Calculate the frequency of the photon absorbed for the excitation from the l = 3 to l = 4 rotational level of this diatomic molecule.

The two oxygen atoms in the O₂ molecule are separated by 0.12 nm. What is the wavelength of the photon emitted when the O₂ goes from = 2 to = 1 rotational states?

The equilibrium separation of the atoms in a given molecule is 0.234 nm and its measured electric dipole moment is 8.76 * 10^-30 C · m. What is the percentage of ionic bonding in this molecule?

The separation distance of the atoms in N₂ (mass = 28 u) is 0.0773 nm. The characteristic rotational energy E_0r for the N₂ molecule is approximately

Gases such as CO₂ and methane are considered greenhouse gases. This is because

The two oxygen atoms in the O₂ molecule are separated by 0.12 nm. What are the values of the two lowest nonzero rotational energies of O₂?

In the absorption spectrum of the diatomic molecule HCl the central frequency is at 8) 67 * 10¹³ Hz, while the absorption peaks on either side are separated by 5.9 *10¹¹ Hz. What is the average moment of inertia of a rotating HCl molecule?

Which one of the following statements is true of the van der Waals bond?

The first two non-zero rotational energies of a N₂ molecule are 0.493 meV and 1.48 meV. The two nitrogen atoms are separated by

The dissociation energy of an ionic compound is the negative of the potential energy of the positive-negative ion system when the ions are

Exam 17: Molecules

When the distance between ions is very small,

When a NaCl molecule is formed from neutral Na and Cl atoms,

The _______ bond is based on the sharing of each valence electron by many atoms.

The bonding of the HF molecule is approximately 43.6% ionic. If its measured electric dipole moment is 6.40 * 10-30 C · m, its equilibrium separation must be

The symmetric wave function Ψ\PsiΨ for two identical, widely separated, finite square wells is best represented by which of the graphs?

The energy of a diatomic molecule can best be understood in terms of

In the absorption spectrum of the diatomic molecule HCl the central frequency is at 8) 67 *1013 Hz, while the absorption peaks on either side are separated by 5.9 *1011 Hz. What is the energy of the lowest vibrational state?

The effective force constant of the CO molecule is 1.86 kN/m. With 12 u for the mass of the carbon atom and 16 u for the mass of the oxygen atom, the frequency of vibration of the CO molecule is

The characteristic energy of rotation E0r for the O2 molecule is 1.78 *10-4 eV. Calculate the frequency of the photon absorbed for the excitation from the l = 3 to l = 4 rotational level of this diatomic molecule.

The two oxygen atoms in the O2 molecule are separated by 0.12 nm. What is the wavelength of the photon emitted when the O2 goes from = 2 to = 1 rotational states?

The equilibrium separation of the atoms in a given molecule is 0.234 nm and its measured electric dipole moment is 8.76 * 10-30 C · m. What is the percentage of ionic bonding in this molecule?

The separation distance of the atoms in N2 (mass = 28 u) is 0.0773 nm. The characteristic rotational energy E0r for the N2 molecule is approximately

The antisymmetric wave function Ψ\PsiΨ for two identical, closely spaced, finite square wells is best represented by which of the graphs?

Gases such as CO2 and methane are considered greenhouse gases. This is because

The figure represents two square wells that are far apart and the symmetric ( Ψ\PsiΨ S) and antisymmetric ( Ψ\PsiΨ A) electron wave functions. Which of the following statements correctly describes the probability distributions and the energies of the wave functions?

The two oxygen atoms in the O2 molecule are separated by 0.12 nm. What are the values of the two lowest nonzero rotational energies of O2?

In the absorption spectrum of the diatomic molecule HCl the central frequency is at 8) 67 * 1013 Hz, while the absorption peaks on either side are separated by 5.9 *1011 Hz. What is the average moment of inertia of a rotating HCl molecule?

Which one of the following statements is true of the van der Waals bond?

The first two non-zero rotational energies of a N2 molecule are 0.493 meV and 1.48 meV. The two nitrogen atoms are separated by

The dissociation energy of an ionic compound is the negative of the potential energy of the positive-negative ion system when the ions are

The bonding of the HF molecule is approximately 43.6% ionic. If its measured electric dipole moment is 6.40 * 10^-30 C · m, its equilibrium separation must be

In the absorption spectrum of the diatomic molecule HCl the central frequency is at 8) 67 10¹³ Hz, while the absorption peaks on either side are separated by 5.9 10¹¹ Hz. What is the energy of the lowest vibrational state?

The characteristic energy of rotation E_0r for the O₂ molecule is 1.78 *10^-4 eV. Calculate the frequency of the photon absorbed for the excitation from the l = 3 to l = 4 rotational level of this diatomic molecule.

The two oxygen atoms in the O₂ molecule are separated by 0.12 nm. What is the wavelength of the photon emitted when the O₂ goes from = 2 to = 1 rotational states?

The equilibrium separation of the atoms in a given molecule is 0.234 nm and its measured electric dipole moment is 8.76 * 10^-30 C · m. What is the percentage of ionic bonding in this molecule?

The separation distance of the atoms in N₂ (mass = 28 u) is 0.0773 nm. The characteristic rotational energy E_0r for the N₂ molecule is approximately

Gases such as CO₂ and methane are considered greenhouse gases. This is because

The two oxygen atoms in the O₂ molecule are separated by 0.12 nm. What are the values of the two lowest nonzero rotational energies of O₂?

In the absorption spectrum of the diatomic molecule HCl the central frequency is at 8) 67 * 10¹³ Hz, while the absorption peaks on either side are separated by 5.9 *10¹¹ Hz. What is the average moment of inertia of a rotating HCl molecule?

The first two non-zero rotational energies of a N₂ molecule are 0.493 meV and 1.48 meV. The two nitrogen atoms are separated by