Chapter 18, Problem 94A

Interpretation Introduction

Interpretation: The effect of adding a catalyst to a slow, reversible reaction on the rate and equilibrium position is to be predicted.

Concept introduction: Any substance that affects the rate of a chemical reaction or reduces the activation conditions (such as heat or pressure) required to initiate that reaction is called a catalyst.

Answer to Problem 94A

A catalyst in a slow, reversible process increases the speed of both forward and backward reactions to the same extent, allowing the system to achieve equilibrium faster. The presence of catalysts does not influence the equilibrium position.

Explanation of Solution

Catalysts are substances that speed up the rate at which a chemical reaction occurs by lowering the amount of activation energy needed to produce an activated complex. In a slow, reversible reaction, a catalyst increases both the forward and reverse reaction rates to the same extent. Eventually, it helps the system attain equilibrium faster.

The catalyst speeds up the process of reaching chemical equilibrium, but it does not cause a change in the equilibrium. Thus, the position of the chemical equilibrium is not affected by the catalyst.

Conclusion

A catalyst in a slow, reversible process increases the speed of both forward and backward reactions to the same extent, allowing the system to achieve equilibrium faster. The presence of catalysts does not influence the equilibrium position.