GENERAL CHEMISTRY II.
PRACTICE MIDTERM
QUESTIONS
1. Write acceptable Lewis structures for the following molecules : (a) H2NOH; (b) O2SCl2
2. Propose a hybridization scheme to account for bonds formed by the central atom in each
of the following molecules (a) hydrogen cyanide, HCN ; (b) acetone, (CH3)2CO
3. Determine the lattice energy of KF(s) from the following data ΔHfo[KF(s)] = -567.3
kJ/mol; enthalpy of sublimation of K(s), 89.24 kJ/mol ; enthalpy of dissociation of F2(g),
159 kJ/mol F2; I1 for K(g), 418.9 kJ/mol; EA for F(g), -328 kJ/mol.
4. Assume that the energy level diagrams apply to the diatomic ions CO+ and CN- .
(a) Predict the bond order of each.
(b) Which of these ions is paramagnetic? Diamagnetic?
(c) Which of these ions do you think has the greater bond length? Explain.
5. How many liters of CH4 (g), measured at 23.4 oC and 768 mmHg, must be burned to
provide the heat needed to vaporize 3.78 L of water at 100 oC ? ∆Hcombustion = -8.90x102
kJ/mol CH4. For H2O(l) at 100 oC, d= 0.958 g/cm3 and ∆Hvap. =40.7 kJ/mol.
Atomic number of ; H : 1, N: 7,
Atomic mass of
C: 6,
O: 8,
S: 16,
; H : 1, N: 14, C: 12, O: 16, S: 32
GOOD LUCK
Cl: 17
Cl: 35.5