Le Châtelier's Principle
| 1. | State Le Châtelier's Principle. | ||
| 2. | What are three stresses that can affect the position of an equilibrium? Identify the one stress that will cause the value of Keq to change. | ||
| 3. | State the effect of a catalyst on equilibrium. | ||
| 4. | Methanol (methyl alcohol; CH3OH) can be manufactured using the following equilibrium reaction: CO(g) + 2 H2 (g) ↔ CH3OH(g) + energy Predict the effect of the following changes on the equilibrium concentration of CH3OH(g). Will it’s concentration increase, decrease, or remain the same? |
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| a. | The temperature of the system is decreased. | ||
| b. | The pressure of the system is increased. | ||
| c. | More H2 (g) is added. | ||
| d. | A catalyst is added to the system. | ||
| 5. | Use Le Châtelier's Principle to predict how the changes listed will affect the following equilibrium reaction: 2 HI(g) + 9.4 kJ ↔ H2 (g) + I2 (g) |
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| a. | Will the concentration of HI increase, decrease, or remain the same if more H2 is added? | ||
| b. | What is the effect on the concentration of HI if the pressure of the system is increased? | ||
| c. | What is the effect on the concentration of HI if the temperature of the system is increased? | ||
| d. | What is the effect on the concentration of HI if a catalyst is added to the system? | ||
| e. | Write the equilibrium constant expression for this reaction. | ||
| f. | At 435°C the equilibrium constant for this reaction is 1.88 × 10-2. Does equilibrium favor the reactants or products? | ||
| 6. | Suggest four ways to increase the concentration of SO3 in the following equilibrium reaction: 2 SO2 (g) + O2 (g) ↔ 2 SO3 (g) + 192.3 kJ |
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| 7. | In the equilibrium reaction: 4 HCl(g) + O2 (g) ↔ 2 H2O(g) + 2 Cl2 (g) + 114.4 kJ Predict the direction of equilibrium shift (forward, reverse, no change) if the following changes occur: |
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| a. | The pressure is increased. | ||
| b. | Heat is added. | ||
| c. | Oxygen is added. | ||
| d. | HCl is removed. | ||
| e. | A catalyst is added. | ||
| 8. | Nitric oxide, NO, releases 57.3 kJ/mol when it reacts with oxygen to give nitrogen dioxide. | ||
| a. | Write a balanced equation for this reaction. | ||
| b. | Write the equilibrium constant expression for this reaction. | ||
| c. | Predict the effect that increasing the temperature will have on: | ||
| 1. | the equilibrium concentration of all reaction participants (NO, O2, and NO2) | ||
| 2. | the numerical value of the equilibrium constant, K(eq) | ||