The activation energies of the forward and backward reactions in the case of a chemical reaction are 37.5 and 51.3 kJ/mole respectively The reaction is

Options

A. Endothermic
B. Exothermic
C. Neither exothermic nor endothermic
D. Independent of temperature

Answer

To determine whether the given reaction is exothermic or endothermic based on the activation energies of the forward and backward reactions, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Given Data**:
- Activation energy of the forward reaction (Ea forward) = 37.5 kJ/mol
- Activation energy of the backward reaction (Ea backward) = 51.3 kJ/mol

2. **Understand the Concept of Activation Energy**:
- Activation energy is the minimum amount of energy required for reactants to undergo a chemical reaction. It is an important factor in determining the nature of the reaction (exothermic or endothermic).

3. **Use the Relationship Between Activation Energies and Enthalpy Change (ΔH)**:
- The change in enthalpy (ΔH) for the reaction can be calculated using the formula:
\[ \Delta H = E_a \text{ (forward)} - E_a \text{ (backward)} \]

4. **Substitute the Values into the Formula**:
- Substitute the activation energies into the equation:
\[ \Delta H = 37.5 \text{ kJ/mol} - 51.3 \text{ kJ/mol} \]

5. **Calculate ΔH**:
- Perform the subtraction:
\[ \Delta H = 37.5 - 51.3 = -13.8 \text{ kJ/mol} \]

6. **Interpret the Result**:
- Since ΔH is negative (-13.8 kJ/mol), this indicates that the reaction releases energy. Therefore, the reaction is exothermic.

7. **Conclusion**:
- Based on the calculated ΔH, we conclude that the reaction is exothermic.

### Final Answer:
The reaction is **exothermic**.

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