Chem 2218
1.
Tutorial 2
Draw Lewis structures for O3 and SO2. For ozone, O-O-O=117º; for sulfur dioxide,
O-S-O=120°. Explain.
2.
(i) Give the shape of the following ions (e.g. linear, angular trigonal planar, trigonal
pyramid, etc.)
a) CO22- b) ClO3(ii) Which of the above ion(s) contain 1 π bond?
(iii) Which of the above ion(s) contain 2 π bonds?
3.
Which of the following molecular is non-linear?
a) SO2
4.
b) CO2
c) HCN
d) C2H2
Using Lewis structures and hybridization concepts,
(a) Predict the bond angles in NO2+ and NO2(b) Predict the relative bond lengths in NO2+ and NO2 and NO2-
5.
Give the structures of (a) SMe2F2, (b) OSF4, (c) [ICl4]-, and (d) XeOF2.
6.
Which of the following in each pair has a smaller bond angle?
(a) NH3 and AsH3
7.
(c) PF5 and IF5
Determine the hybridization for the central atom in
(a) OPCl3
8.
(b) NH3 and NF3
(b) OSF4
(c) OIF5
(d) [I3]-
Determine the hybridization for the central atom in
(a) [PtCl4]2- (has a square planar geometry around Pt)
(b) Cr(CO)6 (has an octahedral geometry around Cr)
(Please specify which p and/or d orbitals are involved in the hybridization.)
9.
Give the bond order and number of unpaired electrons for B2, C2+, and O2-.
10.
Sketch the shapes of the HOMO for each of the following species.
(a) Be2
11.
(b) B2+
(c) C2
Write the electronic configurations and give the bond orders of O22+, O2 and O22-. Which of the
species has the strongest O-O bond? Which of the species should be paramagnetic? Which
species has the longest O-O bond?
12.
Which of N2, NO, O2, C2, F2 and CN would have the bond dissociation energy increased
by (a) addition of an electron to form a negative molecule ion, (b) removal of an electron to
form a positive ion?
13.
Carbon monoxide (CO) form many stable complexes (M-CO) with transition metals. Explain
why CO donates the lone pair on carbon rather than that on oxygen.
14.
(a) Construct the molecular orbital energy level diagram for HF.
(ignore the interaction between F’s 2s and H’s 1s orbitals in constructing your diagram)
(b) Calculate the bond orders for the HF+, HF and HF- species.
(c) Based on the bond orders from (b), consider the H-F bond length changes in the following
two hypothetical processes: HF--->HF+ and HF--->HF-. Do you think which process has more
significant change in the H-F bond length ?
15.
Draw an MO energy-level diagram for the MO’s that would arise in a diatomic
molecule from the combination of unhybridized d orbitals. Label the AO’s being
combined and the resulting MO’s. Let the z axis lie along the σ bond. Please also
sketch the shape of these orbitals.