ap chem unit 7

Ge(g) + 2 Cl2(g) ⇄ GeCl4(g) The value of the equilibrium constant for the reaction represented above is 2.3×10^11. What is the value of the equilibrium constant for the following reaction? 2 GeCl4(g) ⇄ 2 Ge(g) + 4Cl2(g)

1.9x10^-23

Consider the reaction C(s) + CO2(g) ⇄ 2 CO(g). At 1273 K, the Kp value is 167.5. What is the partial pressure, PCO, at equilibrium if PCO2 is 0.17 atm at this temperature?

5.3 atm

For the reaction given below, 2.00 moles of A and 3.00 moles of B are placed in a 6.00-L container. A(g) + 2 B(g) ⇄ C(g) At equilibrium, the concentration of A is 0.213 mol/L. What is the value of K?

8.40

Which of the following are true at equilibrium for the reaction A ⇄ B? I. [A] is no longer changing. II. The overall rate of change of [B] is zero. III. No new molecules of A are converting into B. IV. The value of [B]/[A] is changing in time.

I, II

H2(g) + I2(g) ⇄ 2 HI(g) At 450C, 2.0 moles each of H2(g), I2(g), and HI(g) are combined in a 1.0 L rigid container. The value of Kc at 450C is 50. Which of the following will occur as the system moves toward equilibrium?

More HI(g) will form

A 1.0 L solution AgNO3(ag) of and Pb(NO3)2(aq) has a Ag+ concentration of 0.020 M and a Pb2+ concentration of 0.0010 M. A 0.0010 mol sample of K2SO4(s) is added to the solution. Based on the information in the table above, which of the following will occur? (Assume that the volume change of the solution is negligible.)

Only PbSO4(s) will precipitate.

2 NO(g) + Cl2(g) ⇄ 2 NOCl(g) Kc = 2000 A mixture of NO(g) and Cl2(g) is placed in a previously evacuated container and allowed to reach equilibrium according to the chemical equation shown above. When the system reaches equilibrium, the reactants and products have the concentrations listed in the following table. Species Concentration (M) NO(g) 0.050 Cl2(g) 0.050 NOCl(g) 0.50 Which of the following is true if the volume of the container is decreased by one half?

Q=1000, and the reaction will proceed toward products.

Which of the following leads to the formation of a precipitate in a solubility equilibrium?

Q>Ksp

HCl(aq) + H2O(l) ⇄ H3O+(aq) + Cl−(aq) In 1.0M HCl(aq), HCl is nearly 100 percent dissociated, as represented by the equation above. Which of the following best helps to explain why, in 0.01M HCN(aq), less than 1 percent of HCN is dissociated into ions?

The equilibrium constant for the dissociation of HCN(aq) is much smaller than that for the dissociation of HCl(aq) .

H2O(g) + CO(g) ⇄ CO2(g) + H2(g) Kp =136 at 500K A vessel initially contains H2O(g) at a partial pressure of 0.30atmm, CO(g) at a partial pressure of 0.10atmm, CO2(g) at a partial pressure of 1.5atm, and H2(g) at a partial pressure of 10.atm at 500K.

The partial pressures of H2O(g) and CO(g) increase because Q > Kp.

CuBr(s) ⇄ Cu+(aq) + Br−(aq) Shown above is the chemical equation for the dissolution of the slightly soluble salt CuBr(s). Its Ksp value in pure water was experimentally determined. CuBr was found to be much less soluble in a 0.001M NaBr solution than in pure water. Which of the following correctly explains the decrease in solubility of CuBr in 0.001 M NaBr?

The presence of additional Br− ions already in the solution means equilibrium will be reached when much less CuBr has dissolved.

The reaction quotient for a system is 7.2 × 10^2. If the equilibrium constant for the system is 36, what will happen as equilibrium is approached?

There will be a net gain in reactant.

Co(H2O)62+ + 4 Cl- ⇄ CoCl42- + 6H2O (pink) (blue) When cobalt(II) chloride is added to pure water, the Co2+ ions hydrate by forming attractive interactions with water molecules. The hydrated form then reacts with the Cl- ions to set up the equilibrium shown here. Which statement below describes the change that the system will undergo if hydrochloric acid is added?

Two of these

X(g) + 2 Q(g) ⇄ R(g) + Z(g) Kc = 1.3 × 10^5 at 50°C A 1.0 mol sample of X(g) and a 1.0 mol sample of Q(g) are introduced into an evacuated, rigid 10.0 L container and allowed to reach equilibrium at 50°C according to the equation above. At equilibrium, which of the following is true about the concentrations of the gases?

[R] = [Z] > [Q]

Consider the following reaction (assume an ideal gas mixture): 2 NOBr(g) ⇄ 2 NO(g) + Br2(g) A 1.0-liter vessel was initially filled with pure NOBr, at a pressure of 4.0 atm, at 300 K.After equilibrium was reached, the volume was increased to 2.0 liters, while the temperature was kept at 300 K. The result of this change was

a shift in the equilibrium position to products

N2(g) + 3H2(g) ⇄ 2NH3(g) NH3(g) was synthesized at 200°C in the presence of a powdered Os(s) catalyst, leading to the equilibrium system represented above. Which of the following changes would result in more NH3(g) in the mixture after equilibrium is reestablished?

adding some N2

Given the equation 2 A(g) ⇄ 2 B(g) + C(g). At a particular temperature, K = 1.6 × 10^4.Addition of chemical B to an equilibrium mixture of the above will

cause [A] to increase

For a particular system at a particular temperature there ______ equilibrium constant(s) and there _______ equilibrium position(s) with equilibrium concentrations of reactants and products.

is one; are infinite

Consider the reaction to form calcium chloride dihydrate: CaCl2(s) + 2H2O(g) ⇄ CaCl2·2H2O(s) The equilibrium constant for the reaction as written is:

k= 1/[H2O]^2

Given the equilibrium constants for the following reactions: 4Cu(s) + O2(g) ⇄ 2Cu2O(s) K1 2CuO(s) ⇄ Cu2O(s) + ½O2(g) K2 What is K for the following reaction? 2Cu(s) + O2(g) ⇄ 2CuO(s)

(K1)^1/2 / (K2)

The equilibrium system 2 A ⇄ 2 B + C has a very small equilibrium constant: K = 2.6 × 10^-6. Initially 3.0 moles of A are placed in a 1.5-L flask. Determine the concentration of C at equilibrium.

0.011 M