When `CO_2` is passed through brine solution , saturated with ammonia, white crystals precipitate out these crystals are of

Options

A. `NH_4HCO_3`
B. `NH_4Cl`
C. `Na_2CO_3`
D. `NaHCO_3`

Answer

To solve the question, we need to analyze the reaction that occurs when carbon dioxide (CO₂) is passed through a brine solution saturated with ammonia (NH₃). Here’s a step-by-step breakdown of the process:

### Step 1: Understanding the Components
- **Brine Solution**: This is a concentrated solution of sodium chloride (NaCl) in water.
- **Ammonia Saturation**: The brine is saturated with ammonia, which means NH₃ is dissolved in the solution.

**Hint**: Identify the components involved in the reaction (CO₂, NH₃, NaCl).

### Step 2: Reaction of Ammonia with Water and Carbon Dioxide
- When ammonia is dissolved in water, it forms ammonium hydroxide (NH₄OH).
- When CO₂ is introduced, it reacts with NH₄OH to form ammonium carbonate ((NH₄)₂CO₃).

**Hint**: Remember the reaction of ammonia with water and how CO₂ interacts with it.

### Step 3: Formation of Ammonium Bicarbonate
- The ammonium carbonate can further react with CO₂ and water to form ammonium bicarbonate (NH₄HCO₃).

**Hint**: Consider how ammonium carbonate can convert into ammonium bicarbonate with the addition of CO₂.

### Step 4: Reaction with Sodium Chloride
- The ammonium bicarbonate then reacts with sodium chloride (NaCl) present in the brine solution.
- This reaction leads to the formation of sodium bicarbonate (NaHCO₃) and ammonium chloride (NH₄Cl).

**Hint**: Focus on the interaction between ammonium bicarbonate and sodium chloride.

### Step 5: Precipitation of Sodium Bicarbonate
- Sodium bicarbonate (NaHCO₃) is less soluble in water and precipitates out as white crystals.

**Hint**: Identify the product that precipitates out of the solution.

### Conclusion
- The white crystals that precipitate when CO₂ is passed through a brine solution saturated with ammonia are sodium bicarbonate (NaHCO₃).

**Final Answer**: Sodium hydrogen carbonate (NaHCO₃).