In respect of the equation `k = Ae^(-E_a //RT)` in chemical kinetics, which one of the following statements is correct?

Options

A. k is equilibrium constant
B. A is adsorption factor
C. `E_a` is energy of activation
D. R is Rydberg constant

Explanation

To solve the question regarding the equation \( k = Ae^{-\frac{E_a}{RT}} \) in chemical kinetics, we need to analyze the components of the equation and determine which statement is correct.

### Step-by-Step Solution:

1. **Identify the Equation**:
The equation given is \( k = Ae^{-\frac{E_a}{RT}} \). This is known as the Arrhenius equation, which describes how the rate constant \( k \) of a reaction depends on temperature and activation energy.

2. **Define the Variables**:
- \( k \): This is the rate constant of the reaction.
- \( A \): This is known as the frequency factor or pre-exponential factor. It represents the frequency of collisions and the orientation of reactants.
- \( E_a \): This is the activation energy, which is the minimum energy required for a reaction to occur.
- \( R \): This is the universal gas constant, which is approximately \( 8.314 \, \text{J/(mol·K)} \).
- \( T \): This is the absolute temperature in Kelvin.

3. **Evaluate the Statements**:
- **Statement 1**: "K is equilibrium constant."
- This is incorrect. \( k \) is the rate constant, not the equilibrium constant.
- **Statement 2**: "A is adsorption factor."
- This is also incorrect. \( A \) is the frequency factor or pre-exponential factor, not an adsorption factor.
- **Statement 3**: "E is the energy of activation."
- This is correct. \( E_a \) represents the activation energy of the reaction.
- **Statement 4**: "R is Rydberg constant."
- This is incorrect. \( R \) is the universal gas constant, not the Rydberg constant.

4. **Conclusion**:
Based on the analysis, the correct statement is that **E is the energy of activation**. Therefore, the answer to the question is the third statement.