In the preparation of sodium carbonate (By solvay ammonia soda process) , which of the following is used

Options

A. Slaked lime
B. Quick lime
C. Lime stone
D. NaOH

Answer

To solve the question regarding the preparation of sodium carbonate using the Solvay ammonia-soda process, we can break down the steps involved in the process:

### Step-by-Step Solution:

1. **Understanding the Process**: The Solvay process is an industrial method for producing sodium carbonate from sodium chloride (brine), ammonia, and carbon dioxide.

2. **Starting Materials**: The primary raw materials used in this process are:
- Sodium chloride (NaCl) - commonly known as table salt.
- Ammonia (NH₃) - a compound of nitrogen and hydrogen.
- Carbon dioxide (CO₂) - a gas that is produced from various sources, including the calcination of limestone.

3. **Calcium Carbonate Reaction**: The process begins with the thermal decomposition of calcium carbonate (CaCO₃):
\[ \text{CaCO}_3 \rightarrow \text{CaO} + \text{CO}_2 \]
Here, calcium oxide (CaO) and carbon dioxide (CO₂) are produced.

4. **Ammoniation of Brine**: The brine (sodium chloride solution) is then treated with ammonia:
\[ \text{NaCl} + \text{NH}_3 + \text{H}_2\text{O} \rightarrow \text{NaNH}_2 + \text{HCl} \]
This reaction forms sodium amide and hydrochloric acid.

5. **Carbonation**: The carbon dioxide produced from the previous step is bubbled through the ammoniated brine:
\[ \text{NaNH}_2 + \text{CO}_2 + \text{H}_2\text{O} \rightarrow \text{NaHCO}_3 + \text{NH}_3 \]
This results in the formation of sodium bicarbonate (NaHCO₃).

6. **Formation of Sodium Carbonate**: The sodium bicarbonate is then heated to produce sodium carbonate:
\[ 2\text{NaHCO}_3 \rightarrow \text{Na}_2\text{CO}_3 + \text{CO}_2 + \text{H}_2\text{O} \]
This step yields sodium carbonate (Na₂CO₃), which is the desired product.

7. **Final Product**: The sodium carbonate produced can be crystallized and purified for use in various applications.

### Conclusion:
In the preparation of sodium carbonate by the Solvay ammonia-soda process, the key materials used are **calcium carbonate (CaCO₃)**, **sodium chloride (NaCl)**, **ammonia (NH₃)**, and **carbon dioxide (CO₂)**.

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