Which of the following acts as a poisonous gas ?

Options

A. `COCI_(2)`
B. `C CI_(2)F_(2)`
C. Benzene
D. `CH_(3) CI`

Answer

To determine which of the following compounds acts as a poisonous gas, we will analyze each option provided:

1. **COCl2 (Carbonyl Chloride / Phosgene)**:
- This compound is known as phosgene. It is a highly toxic gas that can cause severe respiratory damage and is considered a poisonous gas.
- **Conclusion**: COCl2 is a poisonous gas.

2. **Chlorofluorocarbon (CFC)**:
- Chlorofluorocarbons are primarily used as refrigerants and in aerosol propellants. While they can have harmful environmental effects (like ozone depletion), they are not classified as poisonous gases.
- **Conclusion**: Chlorofluorocarbon is not a poisonous gas.

3. **Benzene (C6H6)**:
- Benzene is an aromatic hydrocarbon that is known to be carcinogenic (cancer-causing) but is not classified as a poisonous gas in the same sense as phosgene.
- **Conclusion**: Benzene is not a poisonous gas.

4. **CH3Cl (Methyl Chloride)**:
- Methyl chloride is a colorless gas that is used in various industrial applications. It can be harmful and has some toxic effects, but it is not typically classified as a poisonous gas like phosgene.
- **Conclusion**: CH3Cl is not a poisonous gas.

After analyzing all the options, we find that the only compound that acts as a poisonous gas is **COCl2 (Carbonyl Chloride / Phosgene)**.

**Final Answer**: The correct answer is **COCl2 (Carbonyl Chloride / Phosgene)**.

---