Chapter 23, Problem 2ASA

Consider the following reaction at 250C: A(s)+2B(g)C(s)+2D(g) (a) Write an equilibrium constant expression for the reaction. Call the equilibrium constant K1. (b) Write an equilibrium constant expression for the formation of one mole of B(g) and call the equilibrium constant K2. (c) Relate K1 and K2.

Consider the reaction: A(g)+2B(g)+C(s)2D(g)At 25C, only A, B, and C are present. The partial pressures of A, B, and D are given as PA, PB, and PD. Equilibrium is established 18 minutes after the reaction starts. Use terms is less than (LT), is greater than (GT), is equal to (EQ), or insufficient information (X) to answer the following questions. (a) PD at 5 min PA. (b) PA at 21 min PA at 27 min. (c) PB at 7 min PB at 13 min.(d) After 20 min, more B is added. When equilibrium is reestablished, K before the addition K after the addition. (e) After 20 min, the temperature is increased to 35C. PA before the temperature increase PA after the temperature increase after equilibrium is reestablished.

Consider an equilibrium mixture of four chemicals (A, B, C, and D, all gases) reacting in a closed flask according to the equation: A(g)+B(g)C(g)+D(g) a. You add more A to the flask. How does the concentration of each chemical compare to its original concentration after equilibrium is reestablished? Justify your answer. b. You have the original setup at equilibrium, and you add more D to the flask. How does the concentration of each chemical compare to its original concentration after equilibrium is reestablished? Justify your answer.

Kc = 5.6 1012 at 500 K for the dissociation of iodine molecules to iodine atoms. I2(g) 2 I(g) A mixture has [I2] = 0.020 mol/Land [I] = 2.0 108 mol/L. Is the reaction at equilibrium (at 500 K)? If not, which way must the reaction proceed to reach equilibrium?

A 0.72-m01 sample of PCl5 is put into a 1.00-L vessel and heated. At equilibrium, the vessel contains 0.40 mol of PCl3(g ) and 0.40 mol of Cl2(g). Calculate the value of the equilibrium constant for the decomposition of PCl5 to PCl3 and Cl2 at this temperature.

Consider the same reaction as in Question 11. In one experiment 1.0 mole of H2O(g) and 1.0 mole of CO(g) are put into a flask and heated to 350C. In a second experiment 1.0 mole of H2(g) and 1.0 mole of CO2(g) are put into another flask with the same volume as the first. This mixture is also heated to 350C. After equilibrium is reached, will there be any difference in the composition of the mixtures in the two flasks?

Chemical Equilibrium I Part 1: You run the chemical reaction C(aq)+D(aq)2E(aq) at 25C. The equilibrium constant Kc for the reaction at this temperature is 2.0. a Write the equilibrium-constant expression for the reaction. b Can you come up with some possible concentrations of C, D, and E that you might observe when the reaction has reached equilibrium at 25C? What are these values? c A student says that only a very limited number of concentrations for C, D, and E are possible at equilibrium. Is this true? State why you think this is true or is not true. d If you start with 1.0 M concentrations of both C and D and allow the reaction to come to equilibrium, would you expect the concentration of C to have decreased to zero? If not, what would you expect for the concentration of C? (An approximate value is fine.) Part 2: Consider the reaction A(aq)F(aq)+G(aq), whose equilibrium constant is 1.0 105 at 20C. For each of the situations described below, indicate whether any reaction occurs. If reaction does occur, then indicate the direction of that reaction and describe how the concentrations of A, B, F, and G change during this reaction. a A(aq) and B(aq) are mixed together in a container. b F(aq) and G(aq) are mixed together in a container. c A(aq) and F(aq) are mixed together in a container. d B(aq) and G(aq) are mixed together in a container. e Just B(aq) is placed into a container. f Just G(aq) is placed into a container. Consider any one of these situations in which a reaction does occur. At equilibrium, does the reaction mixture have appreciably more products than reactants? If not, how would you describe the equilibrium composition of the reaction mixture? How did you arrive at this answer?

For a typical equilibrium problem, the value of K and the initial reaction conditions are given for a specific reaction, and you are asked to calculate the equilibrium concentrations. Many of these calculations involve solving a quadratic or cubic equation. What can you do to avoid solving a quadratic or cubic equation and still come up with reasonable equilibrium concentrations?

At room temperature, the equilibrium constant Kc for the reaction 2 NO(g) ⇌ N2(g) + O2(g) is 1.4 × 1030. Is this reaction product-favored or reactant-favored? Explain your answer. In the atmosphere at room temperature the concentration of N2 is 0.33 mol/L, and the concentration of O2 is about 25% of that value. Calculate the equilibrium concentration of NO in the atmosphere produced by the reaction of N2 and O2. How does this affect your answer to Question 11?