Heat of neutralisation of a strong dibasic acid in dilute solution by NaOH is nearly :

Options

A. `-27.4` Kcal/eq.
B. `-13.7` Kcal/eq
C. `13.7` Kcal/eq.
D. `-13.7 Kcal/mol

Explanation

To solve the question regarding the heat of neutralization of a strong dibasic acid in dilute solution by NaOH, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Neutralization**:
- Neutralization is the reaction between an acid and a base to form water and a salt. In this case, we are dealing with a strong dibasic acid (like H₂SO₄) and NaOH.

2. **Heat of Neutralization for Strong Acids**:
- The heat of neutralization for strong acids (like HCl) with strong bases (like NaOH) is approximately -13.7 kcal per mole of water formed. This is a standard value for strong acid-strong base reactions.

3. **Dibasic Acid Consideration**:
- A dibasic acid can donate two protons (H⁺ ions). For example, sulfuric acid (H₂SO₄) can release two H⁺ ions when it dissociates.
- When neutralizing a dibasic acid with NaOH, we need to consider how many moles of NaOH are required to fully neutralize the acid.

4. **Calculating Heat of Neutralization**:
- For 1 mole of H₂SO₄, it will react with 2 moles of NaOH to produce 2 moles of water.
- Since the heat of neutralization for strong acids is -13.7 kcal per mole of water formed, for 2 moles of water, the total heat released will be:
\[ \text{Total Heat} = 2 \times (-13.7 \text{ kcal}) = -27.4 \text{ kcal} \]

5. **Conclusion**:
- Therefore, the heat of neutralization of a strong dibasic acid in dilute solution by NaOH is -27.4 kcal per mole of the dibasic acid.

### Final Answer:
- The heat of neutralization of a strong dibasic acid in dilute solution by NaOH is **-27.4 kcal per mole**.