Chemistry Exam 4 Questions

Arrange the following molecules or ions in order of increasing bond energy:
BC+, F2-, C2-, NO+
a. C2+<F2-<NO+<BC+
b. BC+<C2+<F2-<NO+
c. NO+<BC+<C2+<F2-
d. F2-<BC+<C2+<NO+

d. F2-<BC+<C2+<NO+

Two inequalities that describe the buildup of electron density between the nuclei along the bond axis of H2+ are listed below. Fill in the "____________" with the signs that make both inequalities true.
|?1s|^2 _________ 1/2(|1sa|^2 + |1sb|^2) and |?*1s|^

c. >,<

Predict the change in bond length and the change in response to an applied magnetic field when an electron is added to BC.
a. r(e) increases; response to applied magnetic field increases
b. r(e) decreases; response to applied magnetic field increases
c. r

d. r(e) decreases; response to applied magnetic field decreases

Predict the changes in bond length and bond strength when an electron is removed from NO+
a. r(e) increases; D(e) decreases
b. r(e) increases; D(e) increases
c. r(e) decreases; D(e) increases
d. r(e) decreases; D(e) decreases

a. r(e) increases; D(e) decreases

Consider the species NO-, NO, and NO+. Which of these species will be paramagnetic?
a. NO+ and NO-
b. NO+ and NO
c. NO and NO-
d. Only NO-
e. None are paramagnetic

c. NO and NO-

How many ?-type MO's are there in benzene, C6H6?
a. 4
b. 5
c. 6
d. 8

c. 6

In which of the following would the bonding be strengthened with the addition of an electron to form the negative molecular ion?
a. N2
b. O2
c. F2
d. None of these
e. All of these

d. None of these

Which of the following is not true of molecular orbitals?
a. The number of molecular orbitals formed is always equal to the number of atomic orbitals combined.
b. A molecular orbital can accomodate up to two electrons.
c. When the electrons are added to o

e. For any substance, the number of electrons in molecular orbitals is equal to the sum of all valence electrons in molecular orbitals is equal to the sum off all the valence electrons on the bonding atoms.

An antibonding orbital always shows __________electron density on the __________ electronegative atom in a heteronuclear diatomic.
a. more, less
b. more, more
c. less, less

a. more, less

If the pressure of a gas sample is doubled and the absolute temperature is quadrupled, by what factor does the volume of the sample change?
a. 8
b. 2
c. 1/2
d. 1/4
e. 1/8

c. 1/2