Which of the following acid will release maximum amount of heat when completely neutralised by strong base `NaOH`?

Options

A. 1MHCI
B. `1MHNO_(3)`
C. `1MHCIO_(4)`
D. `1MH_(2)SO_(4)`

Answer

To determine which acid releases the maximum amount of heat when completely neutralized by a strong base like NaOH, we can follow these steps:

### Step 1: Identify the Acids
Let's consider the acids given in the options:
1. HCl (Hydrochloric acid)
2. HNO3 (Nitric acid)
3. HClO4 (Perchloric acid)
4. H2SO4 (Sulfuric acid)

### Step 2: Understand the Neutralization Reaction
When an acid (HA) is neutralized by a strong base (NaOH), the reaction can be represented as:
\[ \text{HA} + \text{NaOH} \rightarrow \text{NaA} + \text{H2O} \]
The heat released during this reaction (ΔH) depends on the number of moles of H+ ions produced by the acid.

### Step 3: Determine the Number of H+ Ions
- **HCl** dissociates to give 1 mole of H+.
- **HNO3** dissociates to give 1 mole of H+.
- **HClO4** dissociates to give 1 mole of H+.
- **H2SO4** dissociates to give 2 moles of H+ (it dissociates in two steps:
1. H2SO4 → H+ + HSO4−
2. HSO4− → H+ + SO4^2−)

### Step 4: Compare the Heat Released
Since the heat released (ΔH) is directly proportional to the number of H+ ions produced:
- HCl, HNO3, and HClO4 each produce 1 mole of H+.
- H2SO4 produces 2 moles of H+.

### Step 5: Conclusion
Since H2SO4 produces the highest number of H+ ions (2 moles), it will release the maximum amount of heat when neutralized by NaOH.

Therefore, the acid that releases the maximum amount of heat upon complete neutralization by NaOH is **H2SO4**.

### Final Answer
**H2SO4** (Sulfuric acid) releases the maximum amount of heat when completely neutralized by NaOH.

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