When a concentrated solution of ammonia is saturated with sodium chloride in the presence of pieces of dry ice, a water cloud forms . Thid is due to the ,

Options

A. precipitation of sodium carbonate from the reaction mixture
B. precipitation of sodium hydrogen carbonate from the reaction mixture
C. precipitation of ammonium hydrogen carbonate from the reaction mixture
D. precipitation of ammonium carbonate

Answer

To solve the question regarding the formation of a water cloud when a concentrated solution of ammonia is saturated with sodium chloride in the presence of dry ice, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Components**:
- We have a concentrated solution of ammonia (NH₃).
- Sodium chloride (NaCl) is added to this solution.
- Dry ice (solid carbon dioxide, CO₂) is also present.

2. **Identifying the Reaction**:
- When ammonia is dissolved in water, it forms ammonium hydroxide (NH₄OH).
- The presence of sodium chloride and dry ice introduces CO₂ into the solution.

3. **Chemical Reaction**:
- The reaction can be summarized as:
\[ \text{NH}_3 + \text{H}_2\text{O} + \text{NaCl} + \text{CO}_2 \rightarrow \text{NaHCO}_3 + \text{NH}_4\text{Cl} \]
- Here, sodium bicarbonate (NaHCO₃, also known as sodium hydrogen carbonate) and ammonium chloride (NH₄Cl) are formed.

4. **Formation of the Cloud**:
- Sodium bicarbonate (NaHCO₃) is a solid that can precipitate out of the solution, leading to the formation of a white cloud.
- This cloudiness is due to the precipitation of sodium hydrogen carbonate from the reaction mixture.

5. **Conclusion**:
- The formation of the water cloud is primarily due to the precipitation of sodium hydrogen carbonate (baking soda) from the solution.

### Final Answer:
The water cloud forms due to the precipitation of sodium hydrogen carbonate from the reaction mixture.