In manufacture of sodium carbonate from Solvary (or ammonia soda) process the raw material used is :

Options

A. NaOH
B. `Na_2SO_4`
C. `NaCl`
D. `NaHCO_3`

Explanation

To solve the question regarding the raw materials used in the manufacture of sodium carbonate from the Solvay process, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Solvay Process**: The Solvay process, also known as the ammonia-soda process, is a method for producing sodium carbonate (Na2CO3) from sodium chloride (NaCl), ammonia (NH3), and carbon dioxide (CO2).

2. **Identify the Raw Materials**: The main raw materials used in the Solvay process are:
- Sodium chloride (NaCl)
- Ammonia (NH3)
- Water (H2O)
- Carbon dioxide (CO2)

3. **Chemical Reactions Involved**:
- Ammonia reacts with carbon dioxide and water to form ammonium carbonate:
\[ \text{NH}_3 + \text{CO}_2 + \text{H}_2\text{O} \rightarrow \text{NH}_4\text{HCO}_3 \]
- The ammonium bicarbonate then reacts with sodium chloride to produce sodium bicarbonate and ammonium chloride:
\[ \text{NH}_4\text{HCO}_3 + \text{NaCl} \rightarrow \text{NaHCO}_3 + \text{NH}_4\text{Cl} \]
- Upon heating, sodium bicarbonate decomposes to form sodium carbonate:
\[ 2 \text{NaHCO}_3 \rightarrow \text{Na}_2\text{CO}_3 + \text{CO}_2 + \text{H}_2\text{O} \]

4. **Determine the Correct Option**: From the reactions and the understanding of the process, we can conclude that the primary raw material used in the Solvay process for the manufacture of sodium carbonate is sodium chloride (NaCl).

5. **Final Answer**: The correct answer to the question is sodium chloride (NaCl).