Ethyl amine on heating with `CS_(2)`
in presence of `HgCl_(2)` forms

Options

A. `C_(2)H_(5)NCS`
B. `(C_(2)H_(5))_(2)S`
C. `(C_(2)H_(5))_(2)CS`
D. `C_(2)H_(5)(CS)_(2)`

Explanation

To solve the question regarding the reaction of ethyl amine with carbon disulfide (CS₂) in the presence of mercuric chloride (HgCl₂), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**:
- Ethyl amine (C₂H₅NH₂) is the amine that will react.
- Carbon disulfide (CS₂) is the reagent used in the reaction.
- Mercuric chloride (HgCl₂) acts as a catalyst.

2. **Initial Reaction**:
- When ethyl amine is heated with CS₂, the nitrogen atom (N) in ethyl amine attacks the carbon atom in CS₂. This leads to the formation of a thiourea-like intermediate.
- The reaction can be represented as:
\[ \text{C}_2\text{H}_5\text{NH}_2 + \text{CS}_2 \rightarrow \text{C}_2\text{H}_5\text{N}(\text{C}) + \text{SH}_2 \]

3. **Formation of the Intermediate**:
- The intermediate formed is ethyl thiourea (C₂H₅NCS) after the nitrogen forms a bond with the carbon from CS₂.
- The reaction can be depicted as:
\[ \text{C}_2\text{H}_5\text{N} + \text{CS}_2 \rightarrow \text{C}_2\text{H}_5\text{N}=\text{C}=\text{S} \]

4. **Protonation Step**:
- The intermediate can undergo protonation, where a hydrogen ion (H⁺) from the solution can attach to the nitrogen, leading to the formation of a double bond between nitrogen and carbon.
- The reaction can be represented as:
\[ \text{C}_2\text{H}_5\text{N}=\text{C}=\text{S} \rightarrow \text{C}_2\text{H}_5\text{N}=\text{C}=\text{S} + \text{H}_2\text{S} \]

5. **Final Product**:
- The final product of the reaction is ethyl isothiocyanate (C₂H₅NCS), which can be written as:
\[ \text{C}_2\text{H}_5\text{N}=\text{C}=\text{S} \]

### Conclusion:
The product formed when ethyl amine is heated with carbon disulfide in the presence of mercuric chloride is ethyl isothiocyanate (C₂H₅NCS).