Problem 72c
(c) Calculate the bond order in H2-.
Problem 73b
Draw a picture that shows all three 2p orbitals on one atom and all three 2p orbitals on another atom. (b) How many p bonds can the two sets of 2p orbitals make with each other?
Problem 73c
Draw a picture that shows all three 2p orbitals on one atom and all three 2p orbitals on another atom. (c) How many antibonding orbitals, and of what type can be made from the two sets of 2p orbitals?
Problem 74c
Indicate whether each statement is true or false. c. Antibonding orbitals are higher in energy than bonding orbitals (if all orbitals are created from the same atomic orbitals).
Problem 74d
Indicate whether each statement is true or false. (d) Electrons cannot occupy a nonbonding orbital.
Problem 76
a. Based on its molecular-orbital diagram, what is the bond order of the O2 molecule?
b. What is the expected bond order for the peroxide ion, O22−?
c. What is the expected bond order for the superoxide ion, O2−?
d. From shortest to longest, predict the ordering of the bond lengths for O2, O22−, and O2−.
e. From weakest to strongest, predict the ordering of the bond strengths for O2, O22−, and O2−.
Problem 77
Determine whether each of the following statements about diamagnetism and paramagnetism is true or false:
a. A diamagnetic substance is weakly repelled from a magnetic field.
b. A substance with unpaired electrons will be diamagnetic.
c. A paramagnetic substance is attracted to a magnetic field.
d. The O2 molecule is paramagnetic.
Problem 78
a. Which of the following is expected to be paramagnetic: Ne, Li2, Li2+, N2, N2+, N22−? b. For each of the substances in part (a) that is paramagnetic, determine the number of unpaired electrons it has.
Problem 79d
Using Figures 9.39 and 9.43 as guides, draw the molecular-orbital electron configuration for (d) Ne22+. In each case indicate whether the addition of an electron to the ion would increase or decrease the bond order of the species.
Problem 80b
If we assume that the energy-level diagrams for homonuclear diatomic molecules shown in Figure 9.43 can be applied to heteronuclear diatomic molecules and ions, predict the bond order and magnetic behavior of b. NO–
Problem 80d
If we assume that the energy-level diagrams for homonuclear diatomic molecules shown in Figure 9.43 can be applied to heteronuclear diatomic molecules and ions, predict the bond order and magnetic behavior of d. NeF+
Problem 81a
Determine the electron configurations for CN+, CN, and CN-. (a) Which species has the strongest C¬N bond?
Problem 81b
Determine the electron configurations for CN+, CN, and CN-. b. Which species, if any, is paramagnetic?
Problem 82c2
(c) With what neutral homonuclear diatomic molecules are the NO+ and NO- ions isoelectronic (same number of electrons)? With what neutral homonuclear diatomic molecule is the NO- ion isoelectronic (same number of electrons)?
Problem 83a
Assume that the MOs of diatomics from the third row of the periodic table, such as P2, are analogous to those from the second row.
a. Which valence atomic orbitals of P are used to construct the MOs of P2?
Problem 83c
Assume that the MOs of diatomics from the third row of the periodic table, such as P2, are analogous to those from the second row.
c. For the P2 molecule, how many electrons occupy the MO in the figure?
Problem 84a
The iodine bromide molecule, IBr, is an interhalogen compound. Assume that the molecular orbitals of IBr are analogous to the homonuclear diatomic molecule F2. (a) Which valence atomic orbitals of I and of Br are used to construct the MOs of IBr?
Problem 84c
The iodine bromide molecule, IBr, is an interhalogen compound. Assume that the molecular orbitals of IBr are analogous to the homonuclear diatomic molecule F2. (c) One of the valence MOs of IBr is sketched here. Determine whether each of the following statements about this orbital is true: i. This is an antibonding orbital. ii. The larger contribution is from the I atom. iii. The energy of the molecular orbital is closer in energy to the valence atomic orbitals of Br than to those of I.
Problem 86a
An AB3 molecule is described as having a trigonal-bipyramidal electron-domain geometry. a. How many nonbonding domains are on atom A?
Problem 86b
An AB3 molecule is described as having a trigonal-bipyramidal electron-domain geometry b. Based on the information given, which of the following is the molecular geometry of the molecule:
i. trigonal planar
ii. trigonal pyramidal
iii. T-shaped or
iv. tetrahedral?
Problem 89
Fill in the blank spaces in the following chart. If the molecule column is blank, find an example that fulfills the conditions of the rest of the row. Molecule Electron-Domain Hybridization Dipole Geometry of Central Atom Moment? Yes or No CO2 sp3 Yes sp3 No Trigonal planar No SF4 Octahedral No sp2 Yes Trigonal bipyramidal No XeF2
- From their Lewis structures, determine the number of σ and π bonds in each of the following molecules or ions: (a) hydrazine, N2H4 (b) hydrogen cyanide, HCN (c) sulphur trioxide, SO3
Problem 90
Problem 91e
The lactic acid molecule, CH3CH(OH)COOH, gives sour milk its unpleasant, sour taste. e. What are the approximate bond angles around each carbon atom in the molecule?
Problem 92b
An AB5 molecule adopts the geometry shown here. b. What is the electron-domain geometry for the molecule?
Problem 92c
An AB5 molecule adopts the geometry shown here.
c. Suppose the B atoms are halogen atoms. Of which group in the periodic table is atom A a member:
i. group 5A
ii. group 6A
iii. group 7A
iv. group 8A, or
v. is more information needed?
Problem 94b
The O—H bond lengths in the water molecule (H2O) are 0.96 Å, and the H—O—H angle is 104.5°. The overall dipole moment of the water molecule is 1.85 D. b. Calculate the magnitude of the bond dipole of the O─H bonds. (Note: You will need to use vector addition to do this.)
Problem 95a
a. Predict the electron-domain geometry around the central Xe atom in XeF2, XeF4, and XeF6.
Problem 96
Which of the following statements about hybrid orbitals is or are true? a. After an atom undergoes sp hybridization, there is one unhybridized p orbital on the atom, b. Under 𝑠𝑝2 hybridization, the large lobes point to the vertices of an equilateral triangle, and c. The angle between the large lobes of 𝑠𝑝3 hybrids is 109.5°.
Problem 98a
The molecule C4H5N has the connectivity shown here. a. After the Lewis structure for the molecule is completed, how many 𝜎 and how many 𝜋 bonds are there in this molecule?
Problem 99a
Sodium azide is a shock-sensitive compound that releases N2 upon physical impact. The compound is used in automobile airbags. The azide ion is N3-. (a) Draw the Lewis structure of the azide ion that minimizes formal charge (it does not form a triangle). Is it linear or bent?
Ch.9 - Molecular Geometry and Bonding Theories