At equilibrium, a reversible reaction contains more reactants than products. Both are liquids. The forward reaction requires energy. Which of the following adjustments will increase the amount of product at equilibrium?
1. removing the product
2. adding more product
3. increasing the pressure
4. decreasing the temperature
2. adding more product
To increase the amount of product at equilibrium in a reversible reaction where reactants are in excess, you need to shift the equilibrium towards the products. Let's analyze each option:
1. Removing the product: Removing the product from the system will disturb the equilibrium, causing the reaction to shift in the direction that produces more product to restore equilibrium. This adjustment will increase the amount of product.
2. Adding more product: Adding more product to the system will disturb the equilibrium by increasing the concentration of the products. The reaction will shift in the opposite direction to consume some of the additional product and restore equilibrium. This adjustment will not increase the amount of product.
3. Increasing the pressure: Increasing the pressure has no effect on the equilibrium of a reaction involving only liquids. Therefore, this adjustment will not increase the amount of product.
4. Decreasing the temperature: Lowering the temperature will favor the reaction that absorbs energy. If the forward reaction requires energy, decreasing the temperature will shift the equilibrium towards the reactants. This adjustment will not increase the amount of product.
Based on the above analysis, the adjustments that will increase the amount of product at equilibrium are:
1. Removing the product.
To determine which adjustment will increase the amount of product at equilibrium, let's analyze the given information about the reaction:
1. The reaction is reversible: This means that the reaction can proceed in both the forward and reverse directions.
2. The reactants are in excess compared to the products: At equilibrium, there are more reactants than products, indicating an incomplete reaction.
3. The forward reaction requires energy: This suggests that the forward reaction is endothermic, meaning it absorbs energy from the surroundings.
Now, let's consider each of the given adjustments:
1. Removing the product: Removing the product will disrupt the equilibrium and shift the reaction towards the forward direction, according to Le Chatelier's principle. However, since there are already more reactants than products at equilibrium, removing products would not further increase the amount of product. Therefore, this option is not the correct answer.
2. Adding more product: Adding more product would disrupt the equilibrium and cause the reaction to shift in the reverse direction. This would lead to a decrease in the amount of product and is not the correct answer.
3. Increasing the pressure: In this case, since both reactants and products are liquids, changing the pressure will have no significant effect on the position of the equilibrium. Therefore, this option is not the correct answer.
4. Decreasing the temperature: Since the forward reaction is endothermic (requires energy), decreasing the temperature will favor the forward reaction to absorb more heat and produce more product in an attempt to compensate for the decrease in temperature. Therefore, decreasing the temperature will increase the amount of product at equilibrium, making it the correct answer.
In conclusion, adjusting the reaction by decreasing the temperature will increase the amount of product at equilibrium.