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Problem 69b
(b) If the temperature is raised by 100 K, does the equilibrium constant for this reaction increase or decrease?
Problem 69c
(c) If the temperature is raised by 100 K, does the forward rate constant kf increase by a larger or smaller amount than the reverse rate constant kr?
- Both the forward reaction and the reverse reaction in the following equilibrium are believed to be elementary steps: CO(g) + Cl2(g) Ξ COCl(g) + Cl(g). At 25 _x001F_C, the rate constants for the forward and reverse reactions are 1.4 * 10^-28 M^-1 s^-1 and 9.3 * 10^10 M^-1 s^-1, respectively. (a) What is the value for the equilibrium constant at 25 _x001F_C? (b) Are reactants or products more plentiful at equilibrium?
Problem 71
Problem 74a
When 2.00 mol of SO2Cl2 is placed in a 2.00-L flask at 303 K, 56% of the SO2Cl2 decomposes to SO2 and Cl2: SO2Cl2(g) β SO2(g) + Cl2(g) (a) Calculate Kc for this reaction at this temperature.
Problem 74c
When 2.00 mol of SO2Cl2 is placed in a 2.00-L flask at 303 K, 56% of the SO2Cl2 decomposes to SO2 and Cl2: SO2Cl2(g) β SO2(g) + Cl2(g) (c) According to Le ChΓ’telier's principle, would the percent of SO2Cl2 that decomposes increase, decrease or stay the same if the mixture were transferred to a 15.00-L vessel?
Problem 76b
A sample of nitrosyl bromide (NOBr) decomposes according to the equation 2 NOBr(π) β 2 NO(π) + Br2(π) An equilibrium mixture in a 5.00-L vessel at 100Β°C contains 3.22 g of NOBr, 2.46 g of NO, and 6.55 g of Br2. (b) What is the total pressure exerted by the mixture of gases?
Problem 77c
Consider the hypothetical reaction A(π) β 2 B(π). A flask is charged with 0.75 atm of pure A, after which it is allowed to reach equilibrium at 0Β°C. At equilibrium, the partial pressure of A is 0.36 atm. (c) To maximize the yield of product B, would you make the reaction flask larger or smaller?
Problem 78b
As shown in Table 15.2, the equilibrium constant for the reaction N2(g) + 3 H2(g) β 2 NH3(g) is Kp = 4.34 Γ 10-3 at 300Β°C. Pure NH3 is placed in a 1.00-L flask and allowed to reach equilibrium at this temperature. There are 1.05 g NH3 in the equilibrium mixture. (b) What was the initial mass of ammonia placed in the vessel?
- For the equilibrium 2 IBr(g) β I2(g) + Br2(g), Kp = 8.5 * 10^-3 at 150 _x001F_C. If 0.025 atm of IBr is placed in a 2.0-L container, what is the partial pressure of all substances after equilibrium is reached?
Problem 79
Problem 80b
For the equilibrium PH3BCl3(π ) β PH3(π) + BCl3(π) πΎπ = 0.052 at 60Β°C. (b) A closed 1.500-L vessel at 60Β°C is charged with 0.0500 g of BCl3(π); 3.00 g of solid PH3BCl3 is then added to the flask, and the system is allowed to equilibrate. What is the equilibrium concentration of PH3?
- Solid NH4SH is introduced into an evacuated flask at 24 _x001F_C. The following reaction takes place: NH4SH(s) β NH3(g) + H2S(g). At equilibrium, the total pressure (for NH3 and H2S taken together) is 0.614 atm. What is Kp for this equilibrium at 24 _x001F_C?
Problem 81
Problem 82
A 0.831-g sample of SO3 is placed in a 1.00-L container and heated to 1100 K. The SO3 decomposes to SO2 and O2: 2SO3(π) β 2 SO2(π) + O2(π) At equilibrium, the total pressure in the container is 1.300 atm. Find the values of πΎπ and πΎπ for this reaction at 1100 K.
Problem 84b
Nitric oxide (NO) reacts readily with chlorine gas as follows: 2 NO(π) + Cl2(π) β 2 NOCl(π) At 700 K, the equilibrium constant πΎπ for this reaction is 0.26. For each of the following mixtures at this temperature, indicate whether the mixture is at equilibrium, or, if not, whether it needs to produce more products or reactants to reach equilibrium. (b) πNO = 0.12atm, πCl2 = 0.10atm, πNOCl = 0.050atm
- When 1.50 mol CO2 and 1.50 mol H2 are placed in a 3.00-L container at 395 _x001F_C, the following reaction occurs: CO2(g) + H2(g) β CO(g) + H2O(g). If Kc = 0.802, what are the concentrations of each substance in the equilibrium mixture?
Problem 86
Problem 87a,b
The equilibrium constant constant πΎπ for C(π ) + CO2(π) β 2 CO(π) is 1.9 at 1000 K and 0.133 at 298 K. (a) If excess C is allowed to react with 25.0 g of CO2 in a 3.00-L vessel at 1000 K, how many grams of CO are produced? (b) If excess C is allowed to react with 25.0 g of CO2 in a 3.00-L vessel at 1000 K, how many grams of C are consumed?
Problem 89a
At 700 K, the equilibrium constant for the reaction CCl4(π) β C(π ) + 2 Cl2(π) is πΎπ = 0.76. A flask is charged with 2.00 atm of CCl4, which then reaches equilibrium at 700 K. (a) What fraction of the CCl4 is converted into C and Cl2?
Problem 89b
At 700 K, the equilibrium constant for the reaction CCl4(π) β C(π ) + 2 Cl2(π) is πΎπ = 0.76. A flask is charged with 2.00 atm of CCl4, which then reaches equilibrium at 700 K. (b) What are the partial pressures of CCl4 and Cl2 at equilibrium?
- An equilibrium mixture of H2, I2, and HI at 458 _x001F_C contains 0.112 mol H2, 0.112 mol I2, and 0.775 mol HI in a 5.00-L vessel. What are the equilibrium partial pressures when equilibrium is reestablished following the addition of 0.200 mol of HI?
Problem 91
Problem 92d,e
Consider the hypothetical reaction A(π) + 2 B(π) β 2 C(π), for which πΎπ = 0.25 at a certain temperature. A 1.00-L reaction vessel is loaded with 1.00 mol of compound C, which is allowed to reach equilibrium. Let the variable x represent the number of mol/L of compound A present at equilibrium.
(d) The equation from part (c) is a cubic equation (one that has the form ax3 + bx2 + cx + d = 0). In general, cubic equations cannot be solved in closed form. However, you can estimate the solution by plotting the cubic equation in the allowed range of x that you specified in part (b). The point at which the cubic equation crosses the x-axis is the solution.
(e) From the plot in part (d), estimate the equilibrium concentrations of A, B, and C. (Hint: You can check the accuracy of your answer by substituting these concentrations into the equilibrium expression.)
Problem 93
At a temperature of 700 K, the forward and reverse rate constants for the reaction 2 HI(g) β H2(g) + I2(g) are kf = 1.8Γ10β30 Mβ1sβ1 and kr = 0.063 Mβ1sβ1.
(a) What is the value of the equilibrium constant Kc at 700 K?
(b) Is the forward reaction endothermic or exothermic if the rate constants for the same reaction have values of kf = 0.097βMβ1sβ1 and kr = 2.6 Mβ1sβ1 at 800 K?
- Consider the reaction IO4- (aq) + 2 H2O (l) β H4IO6- (aq); Kc = 3.5 * 10^-2. If you start with 25.0 mL of a 0.905 M solution of NaIO4 and then dilute it with water to 500.0 mL, what is the concentration of H4IO6- at equilibrium?
Problem 94
- At 800 K, the equilibrium constant for the reaction A2(g) β 2 A(g) is Kc = 3.1 Γ 10-4. (d) If the temperature is raised to 1000 K, will the reverse rate constant kr increase or decrease? Will the change in kr be larger or smaller than the change in kf?
Problem 95
- The protein hemoglobin (Hb) transports O2 in mammalian blood. Each Hb can bind 4 O2 molecules. The equilibrium constant for the O2 binding reaction is higher in fetal hemoglobin than in adult hemoglobin. In discussing protein oxygen-binding capacity, biochemists use a measure called the P50 value, defined as the partial pressure of oxygen at which 50% of the protein is saturated. Fetal hemoglobin has a P50 value of 19 torr, and adult hemoglobin has a P50 value of 26.8 torr. Use these data to estimate how much larger Kc is for the aqueous reaction 4 O2(aq) + Hb(aq) β Hb(O2)4(aq) in a fetus, compared to Kc for the same reaction in an adult.
Problem 97