Soda -acid fire extinguisher extinguishes the fire by

Options

A. cutting the supply of air
B. removing the combustible substance
C. raising the ignition temperature
D. none of these .

Explanation

### Step-by-Step Solution

1. **Understanding the Components**:
- A soda-acid fire extinguisher primarily consists of sodium bicarbonate (NaHCO₃) and sulfuric acid (H₂SO₄).

2. **Chemical Reaction**:
- When the fire extinguisher is activated, sulfuric acid reacts with sodium bicarbonate. The chemical reaction can be represented as:
\[ \text{NaHCO}_3 + \text{H}_2\text{SO}_4 \rightarrow \text{Na}_2\text{SO}_4 + \text{H}_2\text{O} + \text{CO}_2 \]
- This reaction produces sodium sulfate, water, and carbon dioxide gas (CO₂).

3. **Mechanism of Fire Extinguishing**:
- The carbon dioxide gas produced during the reaction plays a crucial role in extinguishing the fire.
- **Cooling Effect**: The water produced helps to cool down the combustible materials, lowering their temperature below the ignition point.
- **Cutting Off Air Supply**: The carbon dioxide gas displaces oxygen in the vicinity of the fire. Since fire requires oxygen to sustain combustion, reducing the available oxygen effectively suffocates the fire.

4. **Conclusion**:
- Therefore, a soda-acid fire extinguisher extinguishes fire by cooling the combustible materials and cutting off the air supply through the production of carbon dioxide gas.