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문제 52
For the equilibrium Br2(𝑔) + Cl2(𝑔) ⇌ 2 BrCl(𝑔) at 400 K, 𝐾𝑐 = 7.0. If 0.25 mol of Br2 and 0.55 mol of Cl2 are introduced into a 3.0-L container at 400 K, what will be the equilibrium concentrations of Br2, Cl2, and BrCl?
문제 53
At 373 K, 𝐾𝑝 = 0.416 for the equilibrium 2 NOBr(𝑔) ⇌ 2 NO(𝑔) + Br2(𝑔) If the pressures of NOBr(𝑔) and NO(𝑔) are equal, what is the equilibrium pressure of Br2(𝑔)?
문제 54
At 218°C, 𝐾𝑐 = 1.2×10−4 for the equilibrium NH4SH(𝑠) ⇌ NH3(𝑔) + H2S(𝑔) Calculate the equilibrium concentrations of NH3 and H2S if a sample of solid NH4SH is placed in a closed vessel at 218°C and decomposes until equilibrium is reached.
- Consider the reaction \( \text{CaSO}_4(\text{s}) \rightleftharpoons \text{Ca}^{2+}(\text{aq}) + \text{SO}_4^{2-}(\text{aq}) \) At 25 °C, the equilibrium constant is \( K_c = 2.4 \times 10^{-5} \) for this reaction. (a) If excess \( \text{CaSO}_4(\text{s}) \) is mixed with water at 25 °C to produce a saturated solution of \( \text{CaSO}_4 \), what are the equilibrium concentrations of \( \text{Ca}^{2+} \) and \( \text{SO}_4^{2-} \)? (b) If the resulting solution has a volume of 1.4 L, what is the minimum mass of \( \text{CaSO}_4(\text{s}) \) needed to achieve equilibrium?
문제 55
문제 56a
At 80°C, 𝐾𝑐 = 1.87×10−3 for the reaction PH3BCl3(𝑠) ⇌ PH3(𝑔) + BCl3(𝑔) (a) Calculate the equilibrium concentrations of PH3 and BCl3 if a solid sample of PH3BCl3 is placed in a closed vessel at 80°C and decomposes until equilibrium is reached.
문제 56b
At 80°C, 𝐾𝑐 = 1.87×10−3 for the reaction PH3BCl3(𝑠) ⇌ PH3(𝑔) + BCl3(𝑔) (a) Calculate the equilibrium concentrations of PH3 and BCl3 if a solid sample of PH3BCl3 is placed in a closed vessel at 80°C and decomposes until equilibrium is reached. (b) If the flask has a volume of 0.250 L, what is the minimum mass of PH3BCl3(𝑠) that must be added to the flask to achieve equilibrium?
- For the reaction I2(g) + Br2(g) ⇌ 2 IBr(g), Kc = 280 at 150 _x001F_C. Suppose that 0.500 mol IBr in a 2.00-L flask is allowed to reach equilibrium at 150 _x001F_C. What are the equilibrium concentrations of IBr, I2, and Br2?
문제 57
문제 58
At 25°C, the reaction CaCrO4(𝑠) ⇌ Ca2+(𝑎𝑞) + CrO42−(𝑎𝑞) has an equilibrium constant 𝐾𝑐 = 7.1×10−4. What are the equilibrium concentrations of Ca2+ and CrO42− in a saturated solution of CaCrO4?
- Methane, CH4, reacts with I2 according to the reaction CH4(g) + I2(g) ⇌ CH3I(g) + HI(g). At 630 K, Kp for this reaction is 2.26 × 10^-4. A reaction was set up at 630 K with initial partial pressures of methane at 105.1 torr and I2 at 7.96 torr. Calculate the pressures, in torr, of all reactants and products at equilibrium.
문제 59
문제 61e
Consider the following equilibrium, for which Δ𝐻<0
2 SO2(𝑔) + O2(𝑔) ⇌ 2 SO3(𝑔)
(e) the total pressure of the system is increased by adding a noble gas
문제 61f
Consider the following equilibrium, for which Δ𝐻<0
2 SO2(𝑔) + O2(𝑔) ⇌ 2 SO3(𝑔)
(f) How will each of the following changes affect an equilibrium mixture of the three gases: SO3(𝑔) is removed from the system?
문제 62a,b,c
Consider the reaction 4 NH3(𝑔) + 5 O2(𝑔) ⇌ 4 NO(𝑔) + 6 H2O(𝑔), Δ𝐻 = −904.4 kJ Does each of the following increase, decrease, or leave unchanged the yield of NO at equilibrium? (a) increase [NH3] (b) increase [H2O] (c) decrease [O2]
문제 62d
Consider the reaction 4 NH3(𝑔) + 5 O2(𝑔) ⇌ 4 NO(𝑔) + 6 H2O(𝑔), Δ𝐻 = −904.4 kJ Does each of the following increase, decrease, or leave unchanged the yield of NO at equilibrium? (d) decrease the volume of the container in which the reaction occurs
문제 62e
Consider the reaction 4 NH3(𝑔) + 5 O2(𝑔) ⇌ 4 NO(𝑔) + 6 H2O(𝑔), Δ𝐻 = −904.4 kJ Does each of the following increase, decrease, or leave unchanged the yield of NO at equilibrium? (e) add a catalyst
문제 62f
Consider the reaction 4 NH3(𝑔) + 5 O2(𝑔) ⇌ 4 NO(𝑔) + 6 H2O(𝑔), Δ𝐻 = −904.4 kJ Does each of the following increase, decrease, or leave unchanged the yield of NO at equilibrium? (f) increase temperature.
- How do the following changes affect the value of the equilibrium constant for a gas-phase exothermic reaction: (a) removal of a reactant, (b) removal of a product?
문제 63
- 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?
문제 64
문제 65a
Consider the following equilibrium between oxides of nitrogen 3 NO(g) ⇌ NO2(g) + N2O(g) (a) Use data in Appendix C to calculate ΔH° for this reaction.
문제 65c
Consider the following equilibrium between oxides of nitrogen
3 NO(g) ⇌ 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?
문제 66a
Methanol (CH3OH) can be made by the reaction of CO with H2: CO(𝑔) + 2 H2(𝑔) ⇌ CH3OH(𝑔) (a) Use thermochemical data in Appendix C to calculate ΔH° for this reaction.
문제 66b
Methanol (CH3OH) can be made by the reaction of CO with H2: CO(𝑔) + 2 H2(𝑔) ⇌ CH3OH(𝑔) (b) To maximize the equilibrium yield of methanol, would you use a high or low temperature?
문제 66c
Methanol (CH3OH) can be made by the reaction of CO with H2: CO(𝑔) + 2 H2(𝑔) ⇌ CH3OH(𝑔) (c) To maximize the equilibrium yield of methanol, would you use a high or low pressure?
문제 67
Ozone, O3, decomposes to molecular oxygen in the stratosphere according to the reaction 2 O31g2¡3 O21g2. Would an increase in pressure favor the formation of ozone or of oxygen?
- The water–gas shift reaction CO1g2 + H2O1g2Δ 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)?
문제 68
문제 69a
(a) Is the dissociation of fluorine molecules into atomic fluorine, F2(𝑔) ⇌ 2 F(𝑔), an exothermic or endothermic process?
문제 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) Δ 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?
문제 71
- If Kc = 1 for the equilibrium 2A ⇌ B, what is the relationship between [A] and [B] at equilibrium?
문제 72
- A mixture of CH4 and H2O is passed over a nickel catalyst at 1000 K. The emerging gas is collected in a 5.00-L flask and is found to contain 8.62 g of CO, 2.60 g of H2, 43.0 g of CH4, and 48.4 g of H2O. Assuming that equilibrium has been reached, calculate Kc and Kp for the reaction CH4(g) + H2O(g) ⇌ CO(g) + 3H2(g).
문제 73
- 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). 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.
문제 74