1. Review AP Chem

2. In questions 1 and 2, refer to the electron configuration shown below. (A) 1s 2 2s 2 2p 6 3s 2 3p 4 (B) 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1 3d 5 (C) 1s 2 2s 2 2p 8 3s 2 3p 6 (D) 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 4 (E) 1s 2 2s 2 2p 6 3s 2 3p 6 1. violates the Pauli Exclusion principle 2. electron configuration of Cr

3. In questions 1 and 2, refer to the electron configuration shown below. (A) 1s 2 2s 2 2p 6 3s 2 3p 4 (B) 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1 3d 5 (C) 1s 2 2s 2 2p 8 3s 2 3p 6 (D) 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 4 (E) 1s 2 2s 2 2p 6 3s 2 3p 6 1. violates the Pauli Exclusion principle C 2. electron configuration of Cr B

4. 3. Which of the following has the most polar bond? (A) N 2 (B) F 2 (C) HF (D) HCl (E) PCl 3

5. 3. Which of the following has the most polar bond? (A) N 2 (B) F 2 (C) HF (D) HCl (E) PCl 3

6. 4. Molecules that have planar configurations include which of the following? I. BF 3 II. XeF 4 III. NH 3 (A) I only (B) III only (C) I and II (D) II and III (E) I, II and III

7. 4. Molecules that have planar configurations include which of the following? I. BF 3 II. XeF 4 III. NH 3 (A) I only (B) III only (C) I and II (D) II and III (E) I, II and III

8. 5. Which of the following is most likely to deviate from ideal gas behavior? (A) H 2 (B) He (C) Ne (D) N 2 (E) CCl 4

9. 5. Which of the following is most likely to deviate from ideal gas behavior? (A) H 2 (B) He (C) Ne (D) N 2 (E) CCl 4

10. 6. Which of the following explains why, at room temperature, I 2 is a solid, Br 2 is a liquid and Cl 2 is a gas? (A) Hydrogen bonding (B) Hybridization (C) Ionic Bonding (D) Resonance (E) London dispersion forces

11. 6. Which of the following explains why, at room temperature, I 2 is a solid, Br 2 is a liquid and Cl 2 is a gas? (A) Hydrogen bonding (B) Hybridization (C) Ionic Bonding (D) Resonance (E) London dispersion forces

12. 7. electron configuration of Cr. Which set of quantum numbers (n, l ml, ms) is not possible? (A) 1, 0, 0 ½ (B) 1, 1, 0 ½ (C) 1, 0, 0 -½ (D) 2, 1 -1, ½ (E) 3, 2 1, ½

13. 7. electron configuration of Cr. Which set of quantum numbers (n, l ml, ms) is not possible? (A) 1, 0, 0 ½ (B) 1, 1, 0 ½ (C) 1, 0, 0 -½ (D) 2, 1 -1, ½ (E) 3, 2 1, ½

14. 8. Which of the following has a dipole moment of zero? (A) CCl 4 (B) HCN (C) NO 2 (D) NH 3 (E) H 2 O

15. 8. Which of the following has a dipole moment of zero? (A) CCl 4 (B) HCN (C) NO 2 (D) NH 3 (E) H 2 O

16. 9. Exactly 4.0 g of helium gas, He, is placed into a container at constant temperature and pressure. Next to the container of helium is a 28.0 g sample of nitrogen gas, N 2, placed in an identical container and the same temperature and pressure as the helium. From the list of statements below, select all that are TRUE. I. The number of atoms of He is identical to the number of molecules of N 2. II. The average kinetic energy of the He atoms is the same as the average kinetic energy of the nitrogen molecules. III. The average speed of the helium atoms is the same as the average speed of the nitrogen molecules. (A) I only(C) III only(E) I, II and III (B) II only(D) I and II

17. 9. Exactly 4.0 g of helium gas, He, is placed into a container at constant temperature and pressure. Next to the container of helium is a 28.0 g sample of nitrogen gas, N 2, placed in an identical container and the same temperature and pressure as the helium. From the list of statements below, select all that are TRUE. I. The number of atoms of He is identical to the number of molecules of N 2. II. The average kinetic energy of the He atoms is the same as the average kinetic energy of the nitrogen molecules. III. The average speed of the helium atoms is the same as the average speed of the nitrogen molecules. (A) I only(C) III only(E) I, II and III (B) II only(D) I and II

18. N 2 (g) + 3 F 2 (g)  2 NF 3 (g) ∆H°= – 264 kJ mol –1 ; ∆S°= – 278 J K –1 mol –1 The following questions relate to the synthesis reaction represented by the chemical equation in the box above. (a)Calculate the value of the standard free energy change, for the reaction. (b)Determine the temperature at which the equilibrium constant, K eq, for the reaction is equal to 1.00. (Assume that ∆H˚ and ∆S˚ are independent of temperature.) (c)Calculate the standard enthalpy change, ∆H˚, that occurs when a 0.256 mol sample of NF 3 (g) is formed from N 2 (g) and F 2 (g) at 1.00 atm and 298 K. The enthalpy change in a chemical reaction is the difference between energy absorbed in breaking bonds in the reactants and energy released by bond formation in the products. (d)How many bonds are formed when two molecules of NF 3 are produced according to the equation in the box above? (e)Use both the information in the box above and the table of average bond enthalpies below to calculate the average enthalpy of the F–F bond. Bond Average Bond Enthalpy in kJ/mol -1 : NΞN = 946, N-F = 272, F-F = ?

19. HF(aq) + H 2 O(l)  H 3 O + (aq) + F – (aq) K a = 7.2  10 –4 1. Hydrofluoric acid, HF(aq), dissociates in water as represented by the equation above. (a) Write the equilibrium-constant expression for the dissociation of HF(aq) in water. (b) Calculate the molar concentration of H 3 O + in a 0.40 M HF(aq) solution. HF(aq) reacts with NaOH(aq) according to the reaction represented below. HF(aq) + OH – (aq)  H 2 O(l) + F – (aq) A volume of 15 mL of 0.40 M NaOH(aq) is added to 25 mL of 0.40 M HF(aq) solution. Assume that volumes are additive. (c) Calculate the number of moles of HF(aq) remaining in the solution. (d) Calculate the molar concentration of F – (aq) in the solution. (e) Calculate the pH of the solution.