9. Which one of the following statements is correct?
(A) SO₄ is more energetically stable than XeO₄.
(B) The order of increasing ionization energy in CI⁺ ＞ CI ＞ Se ＞ Se^- is valid.
(C) SeO³ has a T shape structure.
(D) N₂O is a nonpolar molecule.
(E) The AsF5 molecule has a square pyramidal structure.

5. At elevated temperatures, sodium chlorate decomposes to produce sodium chloride and oxygen gas. A 0.8765-g sample of impure sodium chlorate was heated until the production of oxygen gas ceased. The oxygen gas collected over water occupied 57.2 mL at a temperature of 22°C and a pressure of 734 torr. At 22°C the vapor pressure of water is 19.8 torr. The mass percentage of sodium chlorate in the original sample is_____. (A) 46.5% (B) 18.0% (C) 23.3% (D) 76.7% (E) 53.5%

6. Consider the dissolution of CaCl2: CaCl2(s)→Ca2+(aq) +2Cl ̄(aq), △H = -81.5 kJ. An 11.0-g sample of CaCl2 is dissolved in 125 g water, with both substances at 25°C. Assuming no heat loss to the surroundings and assuming the solution has a specific heat capacity of 4.18 J/°C g, the final temperature of the solution is _____°C. (A) 39.2(B) 26.8(C) 14.2(D) 23.7(E) 30.0

7. Which one of the following statements is incorrect? (A) An unknown nonmetal element with a valence electron configuration of ns2np4 has a smaller radius than barium. (B) The set of quantum numbers, n = 4, l = 3, ml = 4 is not allowed in the hydrogen atom. (C) A certain oxygen atom with the electron configuration of 1s22s22px22py2 has no unpaired electrons. (D) The order of increasing first ionization energy among K, Br, Ni is: Br ＜ Ni ＜K (E) (Kr)5s24d105p5 is the expected ground-state electron configuration for the element with one unpaired 5p electron that forms a covalent compound with fluorine.

8. For the transition of n = 3 →n = 2 to occur in the hydrogen atom, the wavelength of the resulting emitted light is _____ nm.(A) 121.6(B) 656.7 (C) 1876(D) 486.4(E) 48.64

10. Consider the following reaction: H2C=CH2(g) + F2(g)→H2FC-CFH2(g), △H = -549 kJ. Please estimate the carbon-fluorine bond energy to be _____ kJ/mol given that the C-C bond energy is 347 kJ/mol, the C=C bond energy is 614 kJ/mol, and the F-F bond energy is 154 kJ/mol. (A) 239 (B)-184(C) -92(D) -327(E) 485

11. Consider three molecules: A, B, and C. Molecule A has a hybridization of sp3. Molecule B has two more effective pairs (electron pairs around the central atom) than molecule A. Molecule C consists of two σ bonds and two π bonds. Thus, which one of the following statements relating to A, B and C is incorrect? (A) Molecule A has a tetrahedral arrangement of electron pairs. (B) Molecule B has a square planar structure. (C) Molecule B has a bond angle of 109.5°. (D) The structure of HCN is similar to C. (E) Molecule C is consistent with a linear arrangement of electron pairs exhibiting sp hybridization.

12. A certain metal fluoride crystalizes in such a way that the fluoride ions occupy simple cubic lattice sites, while the metal ions occupy the body centers of half the cubes. The formula of the metal fluoride is thus_____. (A) MF (B) MF3 (C) MF5 (D) MF4 (E) MF2

13. The solubility of CaCl2 in cold water is 74.5 g per 100.0 g water. Assuming i = 2.6 for CaCl2, the freezing point for a saturated solution of CaCl2 will be _____°C. (A)0 (B) -0.32 (C) -13 (D) -32 (E) -37.4

14.For the reaction A →products, successive half-lives are observed to be 10.0, 20.0 and 40.0 min for an experiment in which [A]0 = 0.10 M. Based on the information, the concentration of A after 30 min of the reaction is ＿ M (A) 0.008 (B) 0.30 (C) 0.025 (D) 0.011 (E) 0.0021

15. Suppose the reaction system 2HI(g)⇌H2(g) + I2(g) has already reached equilibrium. Which of the following statements correctly predict the effect of each change on the equilibrium position? (A) Additional H2(g) added to the system will shift to the right to obtain the equilibrium. (B) As an exothermic reaction, the system will shift to the right to attain the equilibrium when increasing the system temperature. (C) When iodine gas is removed, the system will shift to the left to achieve the equilibrium. (D) Addition of argon gas into the reaction system will shift to the right to achieve the equilibrium. (E) When volume of the reaction container is doubled, the change will have no effects on its equilibrium.