Chemistry 2001 JAMB Past Questions - Question 25: Which of the following best explains the increase in the rate of a chemical reaction as the temperature rises?

Correct Answer

B

Explanation

The increase in the rate of a chemical reaction as the temperature rises can be explained by the collision theory. The collision theory states that for a reaction to occur, reactant particles must collide with sufficient energy and with the correct orientation. When the temperature is increased:

1. **Increased Kinetic Energy:** As the temperature rises, the kinetic energy of molecules also increases. Molecules move faster and collide more frequently.

2. **Increased Collision Frequency:** The higher kinetic energy means that a greater proportion of molecules will have energy equal to or greater than the activation energy of the reaction. Activation energy is the minimum energy required for a reaction to occur. More collisions will have energy equal to or greater than this threshold, increasing the collision frequency.

3. **Effective Collisions:** Not only does temperature increase the frequency of collisions, but it also affects the fraction of collisions that are effective. Effective collisions have sufficient energy and the correct orientation for the reaction to take place. Higher temperatures increase the likelihood of effective collisions.

In summary, the increase in temperature enhances the kinetic energy of molecules, leading to more frequent and more energetic collisions. This, in turn, increases the rate of effective collisions and, consequently, the overall rate of the chemical reaction.