Chapter 14, Problem 42P

12.103 Methanol, CH3OH, can be produced by the reaction of CO with H2, with the liberation of heat. All species in the reaction are gaseous. What effect will each of the following have on the equilibrium concentration of CO? (a) Pressure is increased, (b) volume of the reaction container is decreased, (c) heat is added, (d) the concentration of CO is increased, (e) some methanol is removed from the container, and (f) H2 is added.

For the reaction N2(g)+3H2(g)2NH3(g) show that Kc = Kp(RT)2 Do not use the formula Kp = Kc(RT)5n given in the text. Start from the fact that Pi = [i]RT, where Pi is the partial pressure of substance i and [i] is its molar concentration. Substitute into Kc.

Consider the following system at equilibrium at 25C: PCl3(g)+Cl(g)PCl5(g)G=92.50KJ What will happen to the ratio of partial pressure of PCl5 to partial pressure of PCI3 if the temperature is raised? Explain completely.

What is the approximate value of the equilibrium constant KP for the change C2H5OC2H5(l)C2H5OC2H5(g) at 25 C. {Vapor pressure was described in the previous Chapter on liquids and solids; refer back to this chapter to find the relevant information needed to solve this problem.)

Distinguish between the terms equilibrium constant and reaction quotient. When Q = K, what does this say about a reaction? When Q K, what does this say about a reaction? When Q K. what does this say about a reaction?

Because calcium carbonate is a sink for CO32- in a lake, the student in Exercise 12.39 decides to go a step further and examine the equilibrium between carbonate ion and CaCOj. The reaction is Ca2+(aq) + COj2_(aq) ** CaCO,(s) The equilibrium constant for this reaction is 2.1 X 10*. If the initial calcium ion concentration is 0.02 AI and the carbonate concentration is 0.03 AI, what are the equilibrium concentrations of the ions? A student is simulating the carbonic acid—hydrogen carbonate equilibrium in a lake: H2COj(aq) H+(aq) + HCO}‘(aq) K = 4.4 X 10"7 She starts with 0.1000 AI carbonic acid. What are the concentrations of all species at equilibrium?

Kc for the decomposition of ammonium hydrogen sulfide is 1.8 104 at 25 C. NH4HS(s) NH3(g) + H2S(g) (a) When the pure salt decomposes in a flask, what are the equilibrium concentrations of NH3 and H2S? (b) If NH4HS is placed in a flask already containing 0.020 mol/L of NH3 and then the system is allowed to come to equilibrium, what are the equilibrium concentrations of NH3 and H2S?

At 2300 K the equilibrium constant for the formation of NO(g) is 1.7 103. N2(g) + O2(g) 2 NO(g) (a) Analysis shows that the concentrations of N2 and O2 are both 0.25 M, and that of NO is 0.0042 M under certain conditions. Is the system at equilibrium? (b) If the system is not at equilibrium, in which direction does the reaction proceed? (c) When the system is at equilibrium, what are the equilibrium concentrations?

The decomposition of PCl5(g) to form PCl3(g) and Cl2(g) has Kc = 33.3 at a high temperature. If the initial concentration of PCl5 is 0.1000 M, what are the equilibrium concentrations of the reactants and products?