Solved: You are a member of a research team of chemists

Chapter 17, Problem 17.105

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You are a member of a research team of chemists discussing the plans to operate an ammonia processing plant: (a) The plant operates at close to 700 K, at which Kp is 1.00?10?4 , and employs the stoichiometric 1/3 ratio of N2/H2. N2(g) 3H2(g)BA 2NH3(g) N2(g) H(g) NH(g) N(g) N(g) H(g) NH(g) H2(g)BA 2H(g) log Kp ?17.30 N2(g)BA 2N(g) log Kp ?43.10 BA BA BA BA A B 17.95 Highly toxic disulfur decafluoride decomposes by a freeradical process: . In a study of the decomposition, S2F10 was placed in a 2.0-L flask and heated to 100?C; [S2F10] was 0.50 M at equilibrium. More S2F10 was added, and when equilibrium was reattained, [S2F10] was 2.5 M. How did [SF4] and [SF6] change from the original to the new equilibrium position after the addition of more S2F10? 17.96 A study of the water-gas shift reaction (see 17.37) was made in which equilibrium was reached with [CO] [H2O] [H2] 0.10 M and [CO2] 0.40 M. After 0.60 mol of H2 is added to the 2.0-L container and equilibrium is re-established, what are the new concentrations of all the components? 17.97 A gaseous mixture of 10.0 volumes of CO2, 1.00 volume of unreacted O2, and 50.0 volumes of unreacted N2 leaves an engine at 4.0 atm and 800. K. Assuming that the mixture reaches equilibrium, what are (a) the partial pressure and (b) the concentration (in picograms per liter, pg/L) of CO in this exhaust gas? 2CO2(g) 2CO(g) O2(g) Kp 1.4?10?28 at 800. K (The actual concentration of CO in exhaust gas is much higher because the gases do not reach equilibrium in the short transit time through the engine and exhaust system.) 17.98 Consider the following reaction: (a) What is the apparent oxidation state of Fe in Fe3O4? (b) Actually, Fe has two oxidation states in Fe3O4. What are they? (c) At 900?C, Kc for the reaction is 5.1. If 0.050 mol of H2O(g) and 0.100 mol of Fe(s) are placed in a 1.0-L container at 900?C, how many grams of Fe3O4 are present at equilibrium? Note:The synthesis of ammonia is a major process throughout the industrialized world. 17.99 to 17.105 refer to various aspects of this all-important reaction: 17.99 When ammonia is made industrially, the mixture of N2, H2, and NH3 that emerges from the reaction chamber is far from equilibrium. Why does the plant supervisor use reaction conditions that produce less than the maximum yield of ammonia? 17.100 The following reaction can be used to make H2 for the synthesis of ammonia from the greenhouse gases carbon dioxide and methane: (a) What is the percent yield of H2 when an equimolar mixture of CH4 and CO2 with a total pressure of 20.0 atm reaches equilibrium at 1200. K, at which Kp 3.548?106 ? CH4(g) CO2(g)BA 2CO(g) 2H2(g) N2(g) 3H2(g)BA 2NH3(g) Hrxn ?91.8 kJ 3Fe(s) 4H2O(g)BA Fe3O4(s) 4H2(g) BA S2F10(g)BA SF4(g) SF6(g) siL48593_ch17_737-781 19:11:07 15:04pm Page 780 Apago PDF Enhancer At equilibrium, the partial pressure of NH3 is 50. atm. Calculate the partial pressures of each reactant and Ptotal. (b) One member of the team suggests the following: since the partial pressure of H2 is cubed in the reaction quotient, the plant could produce the same amount of NH3 if the reactants were in a 1/6 ratio of N2/H2 and could do so at a lower pressure, which would cut operating costs. Calculate the partial pressure of each reactant and Ptotal under these conditions, assuming an unchanged partial pressure of 50. atm for NH3. Is the suggestion valid?