Will `NaCN` give a positive Lassaigne's test for nitrogen ?

Answer

To determine whether sodium cyanide (NaCN) will give a positive Lassaigne's test for nitrogen, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Lassaigne's Test:**
The Lassaigne's test is a qualitative analysis method used to detect the presence of nitrogen in organic compounds. It involves the conversion of nitrogen into a soluble sodium salt, which can then be tested for the presence of nitrogen.

2. **Formation of NaCN:**
Sodium cyanide (NaCN) contains both sodium (Na) and cyanide (CN) ions. In the context of Lassaigne's test, the cyanide ion (CN⁻) is the relevant component for detecting nitrogen.

3. **Reaction with Organic Compounds:**
When an organic compound containing nitrogen is heated with sodium metal, it forms sodium cyanide (NaCN). This reaction indicates that nitrogen is present in the organic compound.

4. **Direct Testing with NaCN:**
Since NaCN already contains the cyanide ion, which is a source of nitrogen, we can directly use NaCN in the Lassaigne's test. When NaCN is treated with ferrous sulfate (FeSO₄) and then acidified with hydrochloric acid (HCl), a colored complex is formed, indicating the presence of nitrogen.

5. **Conclusion:**
Therefore, since NaCN contains the cyanide ion, which can be tested for nitrogen, it will indeed give a positive Lassaigne's test for nitrogen.

### Final Answer:
Yes, NaCN will give a positive Lassaigne's test for nitrogen.

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