9. The MO diagram below is appropriate for B₂ (Boron atom), Based on this diagram, B₂
(A)has a bond order of one and is diamagnetic.
(B) has a bond order of one and is paramagnetic.
(C) has a bond order of two and is diamagnetic.
(D) has a bond order of two and is paramagnetic.

5. The symbol [Kr] represents(A) (B)(C) (D)

6. Which have the largest number of unpaired electrons in p orbitals in their ground-state electron configurations? (A)N, As, Bi (B) F, At, Br (C) Ne, Ar, Xe (D) B, Ga, TI

7. Assign formal charges to each atom in the resonance form for SOCl2 given below. (A)0 for Cl, O for S, and O for O (B) 0 for CI, +1 for S, and -1 for O (C) -1 for CI, +4 for S, and -2 for O (D) -1 for CI, -2 for S, and -2 for O

8. Which of the following would be expected to have sp2 hybridization on atom A? (A)II (B) I and III (C) I, Il, and Ill (D) I and IV

10. Calculate the work energy, w, gained or lost by the system when a gas expands from 20 L to 35 L against a constant external pressure of 2.0 atm.[1 Lㆍ atm = 101 J] (A)-5.3 kJ (B) -3.0 kJ (C) +3.0 kJ (D) +5.3 kJ

11. When 50.0 mL of 0.400 M Ca(NO3)2 is added to 50.0 mL of 0.800 M NaF, CaF2 precipitates, as shown in the net ionic equation below. The initial temperature of both solutions is 30.00℃. Assuming that the reaction goes to completion, and that the resulting solution has a mass of 100.00 g and a specific heat of 4.18 J/(g ㆍ ℃), calculate the final temperature of the solution. (A)29.45℃ (B) 30.55℃ (C) 31.10℃ (D) 31.65℃

12. Use the given standard enthalpies of formation to calculate AH" for the following reaction (A)-5213.4 kJ (B)-577.2 kJ (C)-47.2 k (D) +47.2 kJ 

13. For the conversion of water to ice at 25℃ and 1 atm, (A)△G is negative and △H is negative. (B) △G is negative and △H is positive. (C) △G is positive and △H is negative. (D) △G is positive and △H is positive.

14. Each of three identical 15.0-L gas cylinders contains 7.50 mol of gas at 295 K. Cylinder A contains HCN, cylinder B contains NO2, and cylinder C contains O3. According to the kinetic molecular theory, which gas has the highest average kinetic energy? (A)HCN .(B) NO2 (C)O3 (D) All have identical average kinetic energies

15. While mercury is very useful in barometers, mercury vapor is toxic. Given that mercury has a of 59.11 kJ/mol and its normal boiling point is 356.7℃, calculate the vapor pressure in mm Hg at room temperature, 25℃. (A)2.68 x 10-3 mm Hg (B) 2.99 mm Hg (C) 372 mm Hg (D) 753 mm Hg The plots below represent vapor pres assure vs, temperature curves for diethyl ether, ethanol, mercury, and water, not necessarily in that order.