Chapter 18, Problem 99A

Interpretation Introduction

Interpretation: The effect of a catalyst on the collisions between molecules is to be explained.

Concept introduction: A catalyst 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.

Answer to Problem 99A

Catalysts have no effect on collision frequency, but they can increase the frequency of successful collisions.

Explanation of Solution

Catalysts are substances that speed up the rate at which a chemical reaction occurs by reducing the amount of energy required to activate the reaction. However, during collisions between molecules, catalysts can increase the number of successful collisions, even though it does not affect the frequency of collisions.

Conclusion

Catalysts have no effect on collision frequency, but they can increase the frequency of successful collisions.