Which liberates ammonia when treated with

Options

A. `Li_3N`
B. `Mg_3N_2`
C. `CaCN_2`
D. All of these

Answer

To solve the question of which compound liberates ammonia (NH3) when treated with water, we will analyze each option provided: Li3N, Mg3N2, CaCN2, or all of these.

### Step-by-Step Solution:

1. **Understanding the Compounds**:
- **Li3N (Lithium Nitride)**: This is a nitride that can react with water.
- **Mg3N2 (Magnesium Nitride)**: This is also a nitride that can react with water.
- **CaCN2 (Calcium Cyanamide)**: This compound can also release ammonia upon hydrolysis.

2. **Reactions with Water**:
- **Li3N + H2O**:
\[ \text{Li}_3\text{N} + 3\text{H}_2\text{O} \rightarrow 3\text{LiOH} + \text{NH}_3 \]
This reaction shows that lithium nitride reacts with water to produce lithium hydroxide and ammonia.

- **Mg3N2 + H2O**:
\[ \text{Mg}_3\text{N}_2 + 6\text{H}_2\text{O} \rightarrow 3\text{Mg(OH)}_2 + 2\text{NH}_3 \]
Here, magnesium nitride reacts with water to yield magnesium hydroxide and ammonia.

- **CaCN2 + H2O**:
\[ \text{CaCN}_2 + 2\text{H}_2\text{O} \rightarrow \text{CaCO}_3 + \text{NH}_3 \]
In this reaction, calcium cyanamide reacts with water to produce calcium carbonate and ammonia.

3. **Conclusion**:
- Since all three compounds (Li3N, Mg3N2, and CaCN2) liberate ammonia upon reaction with water, the correct answer is **all of these**.

### Final Answer:
The correct option is **D) All of these**.