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- For a certain gas-phase reaction, the fraction of products in an equilibrium mixture is increased by either increasing the temperature or by increasing the volume of the reaction vessel. Does the balanced chemical equation have more molecules on the reactant side or product side?
Problem 64
Problem 65a
Consider the following equilibrium between oxides of nitrogen 3 NO(g) β NO2(g) + N2O(g) (a) Use data in Appendix C to calculate ΞHΒ° for this reaction.
Problem 65c
Consider the following equilibrium between oxides of nitrogen
3 NO(g) β NO2(g) + N2O(g)
(c) At constant temperature, would a change in the volume of the container affect the fraction of products in the equilibrium mixture?
Problem 66a
Methanol (CH3OH) can be made by the reaction of CO with H2: CO(π) + 2 H2(π) β CH3OH(π) (a) Use thermochemical data in Appendix C to calculate ΞHΒ° for this reaction.
Problem 66b
Methanol (CH3OH) can be made by the reaction of CO with H2: CO(π) + 2 H2(π) β CH3OH(π) (b) To maximize the equilibrium yield of methanol, would you use a high or low temperature?
Problem 67
Ozone, O3, decomposes to molecular oxygen in the stratosphere according to the reaction 2 O31g2Β‘3 O21g2. Would an increase in pressure favor the formation of ozone or of oxygen?
- The waterβgas shift reaction CO1g2 + H2O1g2Ξ CO21g2 + H21g2 is used industrially to produce hydrogen. The reaction enthalpy is H = -41 kJ. (b) Could you increase the equilibrium yield of hydrogen by controlling the pressure of this reaction? If so would high or low pressure favor formation of H2(g)?
Problem 68
Problem 69a
(a) Is the dissociation of fluorine molecules into atomic fluorine, F2(π) β 2 ββF(π), an exothermic or endothermic process?
Problem 69b
(b) If the temperature is raised by 100 K, does the equilibrium constant for this reaction increase or decrease?
- 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
- If Kc = 1 for the equilibrium 2A β B, what is the relationship between [A] and [B] at equilibrium?
Problem 72
- 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). Use the equilibrium constant you calculated above to determine the percentage of SO2Cl2 that decomposes when 2.00 mol of SO2Cl2 is placed in a 15.00-L vessel at 303 K.
Problem 74
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?
- A sample of nitrosyl bromide (NOBr) decomposes according to the equation 2 NOBr(g) β 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(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, 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) β 2 NO(g) + Br2(g) An equilibrium mixture in a 5.00-L vessel at 100Β°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 Ξ 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) β 2 B(g). 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. (a) What is the total pressure in the flask at equilibrium?
Problem 77c
Consider the hypothetical reaction A(g) β 2 B(g). 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) 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) β 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) 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
- 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 83
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 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 Γ 10-3 atm
- 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 85
Problem 86a,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?
- NiO is to be reduced to nickel metal in an industrial process using the reaction NiO(s) + CO(g) β Ni(s) + CO2(g). At 1600 K, the equilibrium constant for the reaction is Kp = 6.0 Γ 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