What s true about rate of reaction ?

Options

A. Decrease with increase in temperature
B. Increase with increase in temperature
C. May increase or decrease with increase in temperature
D. Does not depend on temperature

Answer

To determine which statement is true about the rate of reaction, we will analyze the given statements one by one based on the principles of chemical kinetics.

### Step-by-Step Solution:

1. **Statement 1: The rate of reaction decreases with an increase in temperature.**
- This statement is incorrect. Generally, as temperature increases, the kinetic energy of the molecules also increases, leading to more frequent and effective collisions. Therefore, the rate of reaction typically increases with an increase in temperature.

**Hint:** Remember that higher temperatures provide more energy to molecules, increasing their movement and collision frequency.

2. **Statement 2: The rate of reaction increases with an increase in temperature.**
- This statement is correct. According to the collision theory, increasing temperature raises the kinetic energy of the molecules, resulting in more effective collisions. This leads to an increase in the rate of reaction.

**Hint:** Think about how temperature affects molecular motion; more motion means more collisions.

3. **Statement 3: The rate of reaction may increase or decrease.**
- This statement is misleading in the context of temperature. While the rate of reaction can vary due to other factors (like concentration or catalysts), specifically concerning temperature, it does not decrease with an increase in temperature. Thus, this statement is incorrect.

**Hint:** Consider the specific influence of temperature on reaction rates; it is generally consistent.

4. **Statement 4: The rate of reaction does not depend on temperature.**
- This statement is incorrect. The rate of reaction is indeed dependent on temperature, as described by the Arrhenius equation, which shows that the rate constant increases with temperature.

**Hint:** Recall the Arrhenius equation and how it illustrates the relationship between temperature and reaction rate.

### Conclusion:
- The only true statement regarding the rate of reaction is **Statement 2: The rate of reaction increases with an increase in temperature.**