For an exothermic reaqction, the energy of activation of the reactants is

Options

A. equal of the energy of activation of products
B. less than the energy of activation of products
C. greater than the energy of aactivation of products
D. sometimes greater and sometimes less than that of the products

Explanation

To determine the energy of activation of the reactants for an exothermic reaction, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Activation Energy**:
- Activation energy (Ea) is the minimum energy required for reactants to undergo a chemical reaction and form products.

2. **Graphical Representation**:
- For an exothermic reaction, we can represent the energy changes using a graph where the x-axis represents the progress of the reaction and the y-axis represents the energy.
- In this graph, the energy of the reactants is higher than the energy of the products.

3. **Labeling the Graph**:
- Let’s denote the energy of the reactants as \( E_r \) and the energy of the products as \( E_p \).
- The difference in energy between the reactants and products is the enthalpy change (\( \Delta H \)), which is negative for exothermic reactions (\( \Delta H < 0 \)).

4. **Identifying Activation Energies**:
- The activation energy for the reaction (\( E_a \)) is the energy difference between the reactants and the peak of the energy barrier (transition state).
- The activation energy for the products is the energy difference between the products and the peak of the energy barrier.

5. **Comparing Activation Energies**:
- In an exothermic reaction, the activation energy of the reactants (\( E_{a, reactants} \)) is less than the activation energy of the products (\( E_{a, products} \)).
- This means that \( E_{a, reactants} < E_{a, products} \).

6. **Conclusion**:
- Therefore, for an exothermic reaction, the energy of activation of the reactants is less than that of the products.

### Final Answer:
For an exothermic reaction, the energy of activation of the reactants is less than the energy of activation of the products.