ap chemistry units 7 and 8

AgCl (s) ⇌ Ag⁺ (aq) + Cl^- (aq)

In the reversible reaction above:

• K_c = (P_Ag⁺)(P_Cl^-)

• K_c = [Ag⁺][Cl^-]

• K_c = (P_Ag⁺)(P_Cl^-)/(P_AgCl)

• K_c = [Ag⁺][Cl^-]/[AgCl]

N₂ (g) + 3H₂ (g) ⇌ 2NH₃ (g). When the partial pressures of N₂, H₂, and NH₃ are 1.25 atm, 2.00 atm, and 5.00 atm respectively, what does Q equal?

• 0.400

• 0.500

• 2.00

• • 2.50

HF (aq) + H₂O (l) ⇌ F^- (aq) + H₃O⁺ (aq), where K_eq = 6.6 * 10^-4

If [F^-] = 1.0 M, [H₃O⁺] = 1.0 M, and [HF] = 1.0 M, are the reactants or products favored?

• The reactants, since Q < K_eq

• The products, since Q < K_eq

• The reactants, since Q > K_eq

• The products, since Q > K_eq

2NO (g) + Cl₂ (g) ⇌ 2NOCl (g), an exothermic reaction, is performed in a vessel. What can be done to increase the partial pressure of Cl₂?

• Decreasing the volume

• Increasing the partial pressure of NO

• Decreasing the temperature

• Increasing the partial pressure of NOCl

2H₂O (l) ⇌ 2H₂ (g) + O₂ (g) is an endothermic reaction. If the temperature is increased from 300 K to 400 K, how will K_p change?

• K_p will increase because increasing the temperature of an endothermic reaction favors the products

• K_p will decrease because increasing the temperature of an endothermic reaction favors the reactants

• K_p will not change because Kp will still equal (P_H2)²(PO2) even after the temperature is increased

• K_p will not change because it is the volume that affects the equilibrium constant, not the temperature

0.25 moles of Zn(OH)₂ is dissolved into each of three containers. Which container will have the lowest concentration of aqueous Zn⁺ ions?

• 500 mL of distilled water

• 500 mL of 0.25 M aqueous NaOH solution

• 500 mL of 0.25 M aqueous KCl solution

• All three containers will produce the same concentration of Zn⁺ ions

The table shows the partial pressures of H₂, I₂, and HI during the reaction H₂ (g) + I₂ (g) ⇌ 2HI (g).

At which of the following times is the system most likely at equilibrium?

• 5 s

• 15 s

• 25 s

• 35 s

At a given temperature, the Gibbs free energy ΔG° of the equation NaCl (aq) + H₂O (l) ⇌ HCl (aq) + NaOH (aq) is 143.2 kJ/mol. What does this say about the equilibrium constant, K_c?

• K_c < 1 since a positive ΔG° indicates that the reactants are favored over the products

• K_c > 1 since a positive ΔG° indicates that the products are favored over the reactants

• K_c = 0 since a positive ΔG° indicates that the reaction will not occur

• K_c cannot be determined because it is independent of ΔG°

CaF₂ sparsely dissolves in water under the equation CaF₂ (s) ⇌ Ca²⁺ (aq) + 2F^- (aq). If the concentration of Ca²⁺ ions is 1.0 x 10^-4 M at an unknown temperature, what equation can be used to find the Ksp of CaF₂?

• (1.0 x 10^-4)(1.0 x 10^-4)²

• (1.0 x 10^-4)(2.0 x 10^-4)

• (0.50 x 10^-4)^0.5(2.0 x 10^-4)

• (1.0 x 10^-4)(2.0 x 10^-4)²

The reaction PCl₅ (g) ⇌ PCl₃ (g) + Cl₂ (g) has a K_eq of 0.50. What is the K_eq of the reaction 2PCl₅ (g) ⇌ 2PCl₃ (g) + 2Cl₂ (g)?

• 0.25

• 0.50

• • 1.00

• 2.50