Problem 21a
Write an expression for the equilibrium constant of each chemical equation. a. SbCl5(g) ∆ SbCl3(g) + Cl2(g)
Problem 22a
Find and fix each mistake in the equilibrium constant expressions. a. 2 H2S(g) ⇌ 2 H2(g) + S2(g) K = [H2][S2]/[H2S]
Problem 22b
Find and fix each mistake in the equilibrium constant expressions. b. CO(g) + Cl2(g) ⇌ COCl2(g) K = [CO][Cl2]/[COCl2]
Problem 23
When this reaction comes to equilibrium, will the concentra- tions of the reactants or products be greater? Does the answer to this question depend on the initial concentrations of the reac- tants and products? A(g)+B(g) ⇌ 2C(g) Kc = 1.4x10^-5
Problem 24
Ethene (C2H4) can be halogenated by this reaction: C2H4(g) + X2(g) ⇌ C2H4X2(g) where X2 can be Cl2 (green), Br2 (brown), or I2 (purple). Examine the three figures representing equilibrium concentrations in this reaction at the same temperature for the three different hal- ogens. Rank the equilibrium constants for the three reactions from largest to smallest.
Problem 25a
H2 and I2 are combined in a flask and allowed to react according to the reaction: H2(g) + I2(g) ⇌ 2 HI(g) Examine the figures (sequential in time) and answer the questions: a. Which figure represents the point at which equilibrium is reached?
Problem 26
A chemist trying to synthesize a particular compound attempts two different synthesis reactions. The equilibrium constants for the two reactions are 23.3 and 2.2 * 104 at room temperature. However, upon carrying out both reactions for 15 minutes, the chemist finds that the reaction with the smaller equilibrium constant produces more of the desired product. Explain how this might be possible.
Problem 27a
This reaction has an equilibrium constant of Kp = 2.26⨉104 at 298 K. CO(g) + 2 H2(g) ⇌ CH3OH(g) Calculate Kp for each reaction and predict whether reactants or products will be favored at equilibrium. a. CH3OH(g) ⇌ CO(g) + 2 H2(g)
Problem 27b
This reaction has an equilibrium constant of Kp = 2.26⨉104 at 298 K. CO(g) + 2 H2(g) ⇌ CH3OH(g) Calculate Kp for each reaction and predict whether reactants or products will be favored at equilibrium.
b. 1/2 CO(g) + H2 (g) ⇌ 1/2 CH3OH(g)
Problem 27c
This reaction has an equilibrium constant of Kp = 2.26⨉104 at 298 K. CO(g) + 2 H2(g) ⇌ CH3OH(g) Calculate Kp for each reaction and predict whether reactants or products will be favored at equilibrium.
c. 2 CH3OH(g) ⇌ 2 CO(g) + 4 H2(g)
Problem 28a
This reaction has an equilibrium constant of Kp = 2.2⨉106 at 298 K. 2 COF2(g) ⇌ CO2(g) + CF4(g) Calculate Kp for each reaction and predict whether reactants or products will be favored at equilibrium.
a. COF2 (g) ⇌ 1/2 CO2(g) + 1/2 CF4(g)
Problem 28b
This reaction has an equilibrium constant of Kp = 2.2⨉106 at 298 K. 2 COF2(g) ⇌ CO2(g) + CF4(g) Calculate Kp for each reaction and predict whether reactants or products will be favored at equilibrium.
b. 6 COF2(g) ⇌ 3 CO2(g) + 3 CF4(g)
Problem 28c
This reaction has an equilibrium constant of Kp = 2.2⨉106 at 298 K. 2 COF2(g) ⇌ CO2(g) + CF4(g) Calculate Kp for each reaction and predict whether reactants or products will be favored at equilibrium.
c. 2 CO2(g) + 2 CF4(g) ⇌ 4 COF2(g)
Problem 29
Consider the reactions and their respective equilibrium
constants:
NO(g) + 1/2 Br (g) ⇌ NOBr(g) K = 5.3
2NO(g) ⇌ N2(g) + O2(g) Kp = 2.1*10^30
Use these reactions and their equilibrium constants to predict
the equilibrium constant for the following reaction: N2(g) + O2(g) + Br2(g) ⇌ 2NOBr(g)
Problem 31a
Calculate Kc for each reaction. a. I2(g) ⇌ 2I(g) Kp = 6.26 * 10^-22 (at 298K)
Problem 31b
Calculate Kc for each reaction. b. CH4(g) + H2O(g) ⇌ CO(g) + 3 H2(g) Kp = 7.7x10^24 (at 298 K)
Problem 32a
Calculate Kp for each reaction. a. N2O4(g) ⇌ 2NO2(g) Kc = 5.9x10^-3 (at 298 K)
Problem 32b
Calculate Kp for each reaction. b. N2(g) + 3H2(g) ⇌ 2NH3(g) Kc = 3.7x10^8 (at 298 K)
Problem 37
Consider the reaction: N (g) + 3H (g) ⇌ 2NH (g) Complete the table. Assume that all concentrations are equilib- rium concentrations in M. T (K) [n2] [H2] [nH3] Kc 500 0.115 0.105 0.439 575 0.110 ________ 0.128 775 0.120 0.140 ________ ________ 9.6 0.0584
Problem 38
Consider the following reaction: H2(g) + I2(g) ⇌ 2 HI(g) Complete the table. Assume that all concentrations are equilib- rium concentrations in M. T (°C) [H2] [i2] [Hi] Kc 25 0.0355 0.0388 340 ________ 0.0455 445 0.0485 0.0468 0.922 ________ 0.387 9.6 ________ 50.2
Problem 39
Consider the reaction: 2NO(g) + Br2(g) ⇌ 2NOBr(g) Kp = 28.4 at 298K In a reaction mixture at equilibrium, the partial pressure of NO is 108 torr and that of Br2 is 126 torr. What is the partial pressure of NOBr in this mixture?
Problem 40
Consider the reaction: SO2Cl2(g) ⇌ SO2(g) + Cl2(g) Kp = 2.91*10^3 at 298 K In a reaction at equilibrium, the partial pressure of SO2 is 137 torr and that of Cl2 is 285 torr. What is the partial pressure of SO2Cl2 in this mixture?
Problem 47
Consider the reaction: NH4HS(s) ⇌ NH3(g) + H2S(g) At a certain temperature, Kc = 8.5 * 10 - 3. A reaction mixture at this temperature containing solid NH4HS has [NH3] = 0.166 M and [H2S] = 0.166 M. Will more of the solid form or will some of the existing solid decompose as equilibrium is reached?
Problem 49
Silver sulfate dissolves in water according to the reaction: Ag2SO4(s) ⇌ 2Ag+(aq) + SO42-(aq) Kc = 1.1 * 10-5 at298K A 1.5-L solution contains 6.55 g of dissolved silver sulfate. If addi- tional solid silver sulfate is added to the solution, will it dissolve?
Problem 51
Consider the reaction and the associated equilibrium constant: aA(g) ⇌ bB(g) Kc = 4.0 Find the equilibrium concentrations of A and B for each value of a and b. Assume that the initial concentration of A in each case is 1.0 M and that no B is present at the beginning of the reaction. c. a=1;b=2
Problem 53
For the reaction shown here, Kc = 0.513 at 500 K. N2O4(g) ⇌ 2NO2(g) If a reaction vessel initially contains an N2O4 concentration of 0.0500 M at 500 K, what are the equilibrium concentrations of N2O4 and NO2 at 500 K?
Problem 54
For the reaction shown here, Kc = 255 at 1000 K. CO(g) + Cl2(g) ⇌ COCl2(g) If a reaction mixture initially contains a CO concentration of 0.1500 M and a Cl2 concentration of 0.175 M at 1000 K, what are the equilibrium concentrations of CO, Cl2, and COCl2 at 1000 K?
Problem 57
Consider the reaction: HC2H3O2(aq) + H2O(l) ⇌ H3O+(aq) + C2H3O2-(aq) Kc = 1.8 * 10-5 at25°C If a solution initially contains 0.210 M HC2H3O2, what is the equilibrium concentration of H3O + at 25 °C?
Problem 58
Consider the reaction: SO2Cl2(g) ⇌ SO2(g) + Cl2(g) Kc = 2.99 * 10-7 at227°C If a reaction mixture initially contains 0.175 M SO2Cl2, what is the equilibrium concentration of Cl2 at 227 °C?
Problem 61
Consider the reaction: A(g) ⇌ B(g) + C(g) Find the equilibrium concentrations of A, B, and C for each value of Kc. Assume that the initial concentration of A in each case is 1.0 M and that the reaction mixture initially contains no products. Make any appropriate simplifying assumptions. b. Kc = 0.010
Ch.15 - Chemical Equilibrium
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