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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) ⇌ 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) ⇌ SO2(g) + Cl2(g) (c) According to Le Châtelier'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?
- The value of the equilibrium constant Kc for the reaction N2(g) + 3 H2(g) ⇌ 2 NH3(g) changes in the following manner as a function of temperature: Temperature (°C) Kc 300 9.6 400 0.50 500 0.058. (b) Use the standard enthalpies of formation given in Appendix C to determine the ΔH for this reaction at standard conditions. Does this value agree with your prediction from part (a)?
Problem 75
- A sample of nitrosyl bromide (NOBr) decomposes according to the equation 2 NOBr(g) ⇌ 2 NO(g) + Br2(g). An equilibrium mixture in a 5.00-L vessel at 100 _x001F_C contains 3.22 g of NOBr, 3.08 g of NO, and 4.19 g of Br2. (a) Calculate Kc.
Problem 76
Problem 76b
A sample of nitrosyl bromide (NOBr) decomposes according to the equation 2 NOBr(𝑔) ⇌ 2 NO(𝑔) + Br2(𝑔) An equilibrium mixture in a 5.00-L vessel at 100°C contains 3.22 g of NOBr, 3.08 g of NO, and 4.19 g of Br2. (b) What is the total pressure exerted by the mixture of gases?
Problem 76c
A sample of nitrosyl bromide (NOBr) decomposes according to the equation 2 NOBr(g) ⇌ 2 NO(g) + Br2(g) An equilibrium mixture in a 5.00-L vessel at 100°C contains 3.22 g of NOBr, 3.08 g of NO, and 4.19 g of Br2. (c) What was the mass of the original sample of NOBr?
- Consider the hypothetical reaction A1g2 Δ 2 B1g2. A flask is charged with 0.75 atm of pure A, after which it is allowed to reach equilibrium at 0 _x001F_C. At equilibrium, the partial pressure of A is 0.36 atm. (a) What is the total pressure in the flask at equilibrium?
Problem 77
Problem 77a
Consider the hypothetical reaction A(g) ⇌ 2 B(g). A flask is charged with 0.75 atm of pure A, after which it is allowed to reach equilibrium at 0°C. At equilibrium, the partial pressure of A is 0.36 atm. (a) What is the total pressure in the flask at equilibrium?
Problem 77c
Consider the hypothetical reaction A(g) ⇌ 2 B(g). A flask is charged with 0.75 atm of pure A, after which it is allowed to reach equilibrium at 0°C. At equilibrium, the partial pressure of A is 0.36 atm. (c) What could we do to maximize the yield of B?
- As shown in Table 15.2, the equilibrium constant for the reaction N2(g) + 3 H2(g) ⇌ 2 NH3(g) is Kp = 4.34 * 10^-3 at 300 _x001F_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. (a) What are the masses of N2 and H2 in the equilibrium mixture? (b) What is the total pressure in the vessel?
Problem 78
Problem 78b
As shown in Table 15.2, the equilibrium constant for the reaction N2(g) + 3 H2(g) ⇌ 2 NH3(g) is Kp = 4.34 × 10-3 at 300°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) ⇌ 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(𝑠) ⇌ PH3(𝑔) + BCl3(𝑔) 𝐾𝑝 = 0.052 at 60 °C. (b) After 3.00 g of solid PH3BCl3 is added to a closed 1.500-L vessel at 60 °C, the vessel is charged with 0.0500 g of BCl3(𝑔). 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) ⇌ 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(𝑔) ⇌ 2 SO2(𝑔) + O2(𝑔) At equilibrium, the total pressure in the container is 1.300 atm. Find the values of 𝐾𝑝 and 𝐾𝑐 for this reaction at 1100 K.
Problem 83
Nitric oxide (NO) reacts readily with chlorine gas as follows: 2 NO(𝑔) + Cl2(𝑔) ⇌ 2 NOCl(𝑔) At 700 K, the equilibrium constant Kp for this reaction is 0.26. Predict the behavior of each of the following mixtures at this temperature and indicate whether or not the mixtures are at equilibrium. If not, state whether the mixture will need to produce more products or reactants to reach equilibrium.
(a) PNO = 0.15 atm, PCl2 = 0.31 atm, PNOCl = 0.11 atm
(b) PNO = 0.12 atm, PCl2 = 0.10 atm, PNOCl = 0.050 atm
(c) PNO = 0.15 atm, PCl2 = 0.20 atm, PNOCl = 5.10 × 10-3 atm
Problem 84
At 900 °C, 𝐾𝑐 = 0.0108 for the reaction
CaCO3(𝑠) ⇌ CaO(𝑠) + CO2(𝑔)
A mixture of CaCO3, CaO, and CO2 is placed in a 10.0-L vessel at 900°C. For the following mixtures, will the amount of CaCO3 increase, decrease, or remain the same as the system approaches equilibrium?
(a) 15.0 g CaCO3, 15.0 g CaO, and 4.25 g CO2
(b) 2.50 g CaCO3, 25.0 g CaO, and 5.66 g CO2
(c) 30.5 g CaCO3, 25.5 g CaO, and 6.48 g CO2
- 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) ⇌ CO(g) + H2O(g). If Kc = 0.802, what are the concentrations of each substance in the equilibrium mixture?
Problem 85
Problem 86a,b
The equilibrium constant constant 𝐾𝑐 for C(𝑠) + CO2(𝑔) ⇌ 2 CO(𝑔) 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?
- NiO is to be reduced to nickel metal in an industrial process using the reaction NiO(s) + CO(g) ⇌ Ni(s) + CO2(g). At 1600 K, the equilibrium constant for the reaction is Kp = 6.0 × 10^2. If a CO pressure of 150 torr is to be employed in the furnace and the total pressure never exceeds 760 torr, will reduction occur?
Problem 87
- What does this anecdote tell us about the equilibrium constant for the reaction of iron oxide with carbon monoxide to produce elemental iron and CO2?
Problem 88
Problem 89a
At 700 K, the equilibrium constant for the reaction CCl4(𝑔) ⇌ C(𝑠) + 2 Cl2(𝑔) is 𝐾𝑝 = 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(𝑔) ⇌ C(𝑠) + 2 Cl2(𝑔) is 𝐾𝑝 = 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(𝑔) + 2 B(𝑔) ⇌ 2 C(𝑔), for which 𝐾𝑐 = 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 94
At a temperature of 700 K, the forward and reverse rate constants for the reaction 2 HI(g) ⇌ H2(g) + I2(g) are kf = 1.8×10−30 M−1s−1 and kr = 0.063 M−1s−1.
(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 = 0.097 M−1s−1 and kr = 2.6 M−1s−1 at 800 K?
- Consider the reaction IO4- (aq) + 2 H2O (l) ⇌ 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 95
- The following equilibria were measured at 823 K: CoO(s) + H2(g) ⇄ Co(s) + H2O(g) Kc = 67; H2(g) + CO2(g) ⇄ CO(g) + H2O(g) Kc = 0.14. (c) If you were to place 5.00 g of CoO(s) in a sealed tube with a volume of 250 mL that contains CO(g) at a pressure of 1.00 atm and a temperature of 298 K, what is the concentration of the CO gas? Assume there is no reaction at this temperature and that the CO behaves as an ideal gas (you can neglect the volume of the solid).
Problem 96
Problem 96a
The following equilibria were measured at 823 K: CoO(s) + H2(g) ⇌ Co(s) + H2O(g) Kc = 67 H2(g) + CO2(g) ⇌ CO(g) + H2O(g) Kc = 0.14 (a) Use these equilibria to calculate the equilibrium constant, Kc, for the reaction CoO(s) + CO(g) ⇌ Co(s) + CO2(g) at 823 K.
Problem 96d
The following equilibria were measured at 823 K: CoO(s) + H2(g) ⇌ Co(s) + H2O(g) Kc = 67 H2(g) + CO2(g) ⇌ CO(g) + H2O(g) Kc = 0.14 (d) If the reaction vessel from part (c) is heated to 823 K and allowed to come to equilibrium, how much CoO(s) remains?