The rate constant of a reaction changes with

Options

A. Pressure
B. Temperature
C. Initial concentration of reactants
D. Extent of reaction

Answer

To solve the question regarding the factors that affect the rate constant of a reaction, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Rate Constant**: The rate constant (k) is a proportionality factor in the rate equation of a chemical reaction. It relates the rate of reaction to the concentration of reactants.

2. **Factors Affecting Rate of Reaction**: The rate of a chemical reaction can be influenced by several factors, including:
- Concentration of reactants
- Temperature
- Pressure (for gaseous reactions)
- Surface area of solid reactants
- Presence of catalysts

3. **Identifying the Unique Factor for Rate Constant**: While the rate of reaction can be influenced by multiple factors, the rate constant itself is primarily affected by temperature.

4. **Temperature's Role**: As temperature increases, the kinetic energy of the molecules increases, leading to more frequent and effective collisions, which in turn increases the rate constant.

5. **Conclusion**: Therefore, the rate constant of a reaction changes with temperature. It does not change with concentration, pressure, or surface area.

### Final Answer:
The rate constant of a reaction changes with **temperature**.

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