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19 Chemical Thermodynamics Solutions to Exercises (c) = 0 at equilibrium (d) = + RT [OH⁻] = 1 = 1.4925 X 10⁻⁶= 1.5 10⁻⁶ 0.098 Additional Exercises 19.87 (a) The thermodynamic quantities T, E, and S are state functions. T is directly related to the distribution of molecular speeds, which does not depend on the path from one state to another. (b) The quantities q and W do depend on the path taken from one state to another. (c) There is only one reversible path between states. (d) Isothermal processes occur at constant T. Since the process is reversible, q is and W is 19.88 (a) False. The essential question is whether the reaction proceeds far to the right before arriving at equilibrium. The position of equilibrium, which is the essential aspect, is not only dependent on AH but on the entropy change as well. (b) True. (c) True. (d) False. Nonspontaneous processes in general require that work be done to force them to proceed. Spontaneous processes occur without application of work. (e) False. Such a process might be spontaneous, but would not necessarily be so. Spontaneous processes are those that are exothermic and/or that lead to increased disorder in the system. 19.89 Process AH AS (a) + + (b) I - (c) + + (d) + + (e) - + 19.90 There is no inconsistency. The second law states that in any spontaneous process there is an increase in the entropy of the universe. While there may be a decrease in entropy of the system, as in the present case, this decrease is more than offset by an increase in entropy of the surroundings. 19.91 (a) Each of the 4 molecules can be in either the left or the right bulb. Thus, there are (2)⁴ = 16 arrangements. (b) Only one arrangement has all 4 molecules in the left flask. 599