On increasing the temperature by 10K, the rate of reaction becomes double. Which of the following is the most appropriate reason?

Options

A. With increase of temperature, velocities increase and hence the number of collisions are appreciably increased
B. The activation energy decreases with increase of temperature
C. The bonds between the atoms of the reacting molecules become weak at higher temperatures
D. The higher the temperature, large is the fraction of colliding particles which can cross the energy barrier

Explanation

To solve the question regarding the increase in reaction rate upon increasing the temperature by 10K, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Reaction Rate and Temperature**:
- The rate of a chemical reaction is influenced by various factors, including temperature. An increase in temperature typically leads to an increase in the reaction rate.

2. **Effect of Temperature on Molecular Collisions**:
- As the temperature increases, the kinetic energy of the molecules also increases. This means that the molecules move faster and collide more frequently.

3. **Collisions and Activation Energy**:
- For a reaction to occur, the colliding molecules must have enough energy to overcome the activation energy barrier. The activation energy is the minimum energy required for a reaction to take place.

4. **Increased Collisions Leading to Higher Rate**:
- With more frequent collisions and higher kinetic energy, a greater fraction of the colliding molecules will have enough energy to overcome the activation energy barrier. This results in a higher rate of reaction.

5. **Conclusion**:
- Therefore, the most appropriate reason for the doubling of the reaction rate upon increasing the temperature by 10K is that a higher temperature increases the fraction of colliding particles that can cross the energy barrier.

### Final Answer:
The correct option is: "The higher the temperature, the larger the fraction of the colliding particles that can cross the energy barrier."