1 .		The following equilibrium was obtained when some NO gas was placed into a 2.00-L container until the pressure was 0.650 atm: 2NO(g) N2(g) + O2(g) The equilibrium pressure of N2 was found to be 5.25 x 10-2 atm. What is Keq for this reaction? Online Text [Hint]
2 .		When solid NH4HS is placed in a closed flask at 28°C, the solid dissociates according to the equation: NH4HS(s) NH3(g) + H2S(g). The total pressure of the equilibrium mixture is 0.766 atm. Determine Keq at this temperature. Online Text [Hint]
3 .		At 1200 K, the approximate temperature of automobile exhaust gases, Keq for the reaction 2CO2(g) 2CO(g) + O2(g) is about 1 x 10-13. Assuming that the exhaust gas (total pressure 1 atm) by volume contains 0.2 percent CO, 12 percent CO2, and 3 percent O2, is the system at equilibrium with respect to the above reaction? Online Text [Hint]
4 .		At 100°C the equilibrium constant for the reaction COCl2(g) CO(g) + Cl2(g) has the value of Keq = 2.19 x 10-10. Are the following mixtures of COCl2, CO, and Cl2 at equilibrium? If not, indicate the direction that the reaction must proceed to achieve equilibrium. (i) PCOCl2 = 5.00 x 10-2 atm; PCO = 3.31 x 10-6 atm; PCl2 = 3.31 x 10-6 atm (ii) PCOCl2 = 3.50 x 10-3 atm; PCO = 1.11 x 10-5 atm; PCl2 = 3.25 x 10-6 atm Online Text [Hint]
5 .		A 2.21-L vessel was found to contain 4.18 x 10-2 mol of CO2, 2.81 x 10-2 mol of CO, and 8.89 x 10-3 mol of O2 at 298 K. Is the system at equilibrium for the reaction 2CO2 2CO + O2? If not, which direction must the reaction proceed to achieve equilibrium? (Keq = 1.2 x 10-13) Online Text [Hint]
6 .		At 100°C, Keq = 0.078 for the following reaction: SO2Cl2(g) SO2(g) + Cl2(g) In an equilibrium mixture of the three gases the partial pressures of SO2Cl2 and SO2 are 0.136 atm and 0.072 atm, respectively. What is PCl2 in the equilibrium mixture? Online Text [Hint]
7 .		At 500 K the equilibrium constant for the reaction 2NO(g) + Cl2(g) 2NOCl(g) is Keq = 52.0. An equilibrium mixture of the three gases has partial pressures of 0.095 atm and 0.171 atm for NO and Cl2, respectively. What is the partial pressure of NOCl in the mixture? Online Text [Hint]
8 .		At 2000°C the equilibrium constant for the reaction 2NO(g) N2(g) + O2(g) is Keq = 2.400 x 103. If the initial partial pressure of NO is 0.5000 atm, what are the equilibrium partial pressures of NO, N2, and O2? Online Text [Hint]
9 .		For the equilibrium 2IBr(g) I2(g) + Br2(g), Keq = 8.5 x 10-3 at 150°C. If 0.040 atm of IBr is placed in a 1.0-L container, what is the partial pressure of this substance after equilibrium is reached? Online Text [Hint]
10 .		Consider the following equilibrium: Cl2(g) + F2(g) 2ClF(g) with Keq = 19.9 If we begin with 0.100 atm chlorine and 0.100 atm fluorine, what are the partial pressures of ClF and F2 at equilibrium? Online Text [Hint]
11 .		Consider the reaction C(graphite) + CO2(g) 2CO(g), which has the equilibrium constant Keq = 3.7 x 10-23 at 25°C. What is the concentration of CO at equilibrium if we start with 0.22 g of CO2 per liter? Online Text [Hint]
12 .		At 1800 K the equilibrium constant is Keq = 1.03 x 10-4 for the reaction N2(g) + O2(g) 2NO(g). What is the equilibrium partial pressure of NO in air, which has an initial total pressure of 1.000 atm if the composition of air is 80.0 percent N2 and 20.0 percent O2? Online Text [Hint]
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