In the manufacture of sodium carbonate, following reactions are involved:
`(A) overset(Delta)rarr (B) + CO_(2)`
`(B) +H_(2)O rarr (C ) overset(+NH_(4)Cl rarr (D)overset(+H_(2)O)rarr underset("Solution")(E )`
`(E )+CO_(2)rarr (F)`
`(F)+NaCl rarr (G) overset("Heat")rarr Na_(2)CO_(3)+CO_(2)+H_(2)O`
(D) is a gas which is soluble in `H_(2)O`
The name of the process is

Options

A. Solvay
B. Salt cake
C. Lowing
D. Gossage

Explanation

To solve the question regarding the manufacture of sodium carbonate and identify the name of the process, we can break it down step by step:

### Step-by-Step Solution:

1. **Identify the Initial Reaction (A to B)**:
- The reaction starts with the thermal decomposition of calcium carbonate (CaCO₃). When heated, it decomposes into calcium oxide (CaO) and carbon dioxide (CO₂).
- **Reaction**:
\[ \text{CaCO}_3 \overset{\Delta}{\rightarrow} \text{CaO} + \text{CO}_2 \]
- Here, B is CaO.

2. **Formation of Calcium Hydroxide (B + H₂O to C)**:
- Calcium oxide (B) reacts with water (H₂O) to form calcium hydroxide (C).
- **Reaction**:
\[ \text{CaO} + \text{H}_2\text{O} \rightarrow \text{Ca(OH)}_2 \]
- Here, C is Ca(OH)₂.

3. **Reaction with Ammonium Chloride (C + NH₄Cl to D)**:
- Calcium hydroxide (C) reacts with ammonium chloride (NH₄Cl) to produce ammonia gas (D), calcium chloride, and water.
- **Reaction**:
\[ \text{Ca(OH)}_2 + 2\text{NH}_4\text{Cl} \rightarrow 2\text{NH}_3 \text{(gas)} + \text{CaCl}_2 + 2\text{H}_2\text{O} \]
- Here, D is NH₃ (ammonia gas).

4. **Formation of Ammonium Hydroxide (D + H₂O to E)**:
- Ammonia gas (D) dissolves in water to form ammonium hydroxide (E).
- **Reaction**:
\[ \text{NH}_3 + \text{H}_2\text{O} \rightarrow \text{NH}_4\text{OH} \]
- Here, E is NH₄OH.

5. **Reaction of Ammonium Hydroxide with CO₂ (E + CO₂ to F)**:
- Ammonium hydroxide (E) reacts with carbon dioxide (CO₂) to form ammonium bicarbonate (F).
- **Reaction**:
\[ \text{NH}_4\text{OH} + \text{CO}_2 \rightarrow \text{NH}_4\text{HCO}_3 \]
- Here, F is NH₄HCO₃.

6. **Reaction with Sodium Chloride (F + NaCl to G)**:
- Ammonium bicarbonate (F) reacts with sodium chloride (NaCl) to produce sodium bicarbonate (G) and ammonium chloride.
- **Reaction**:
\[ \text{NH}_4\text{HCO}_3 + \text{NaCl} \rightarrow \text{NaHCO}_3 + \text{NH}_4\text{Cl} \]
- Here, G is NaHCO₃.

7. **Heating Sodium Bicarbonate (G to Na₂CO₃)**:
- Sodium bicarbonate (G) is heated to produce sodium carbonate (Na₂CO₃), carbon dioxide, and water.
- **Reaction**:
\[ 2\text{NaHCO}_3 \overset{\Delta}{\rightarrow} \text{Na}_2\text{CO}_3 + \text{CO}_2 + \text{H}_2\text{O} \]

8. **Identify the Process**:
- The entire series of reactions described is known as the **Solvay Process** (or Solvay Ammonia Process), which is used for the manufacture of sodium carbonate.

### Final Answer:
The name of the process is **Solvay Process**.

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