Chloropicrin is obtained by the reaction of

Options

A. Nitric acid on chlorobenzene
B. Chlorine on picric acid
C. Nitric acid on chloroform
D. Steam on carbon tetrachloride

Answer

To determine how chloropicrin is obtained, we need to analyze the given options and identify the correct reaction.

### Step-by-Step Solution:

1. **Identify the Compound**: Chloropicrin is a chemical compound with the formula CCl3NO2. It is also known as trichloronitromethane.

2. **Examine the Options**:
- **Option 1**: Nitric acid on chlorobenzene
- **Option 2**: Chlorine on picric acid
- **Option 3**: Nitric acid on chloroform
- **Option 4**: Steam on carbon tetrachloride

3. **Analyze Option 3**:
- The reaction of chloroform (CHCl3) with concentrated nitric acid (HNO3) is known to produce chloropicrin.
- The reaction mechanism involves the substitution of hydrogen atoms in chloroform with nitro groups from nitric acid.

4. **Write the Reaction**:
- The balanced chemical reaction can be represented as follows:
\[ \text{CHCl}_3 + \text{HNO}_3 \rightarrow \text{CCl}_3\text{NO}_2 + \text{H}_2\text{O} \]
- Here, one hydrogen atom from chloroform is replaced by a nitro group, resulting in chloropicrin (CCl3NO2) and water (H2O).

5. **Conclusion**: Based on the analysis, the correct answer is **Option 3**: Chloropicrin is obtained by the reaction of nitric acid on chloroform.