Carcinogen present in coal taris

Options

A. Nitroso dimethylen
B. 3,4-Benzopyrene
C. 2-Naphthylamine
D. 4-amino biphenyl

Answer

### Step-by-Step Solution:

1. **Understanding Coal Tar**:
- Coal tar is a thick, black liquid that is a byproduct of the carbonization of coal. It contains a complex mixture of hydrocarbons, including aromatic hydrocarbons.

2. **Identifying Carcinogens**:
- Carcinogens are substances that can lead to cancer in living tissue. In the context of coal tar, we need to identify which specific carcinogenic compounds are present.

3. **Evaluating the Options**:
- The question provides several options for potential carcinogens found in coal tar. We need to evaluate each option to determine which one is correct.

4. **Option Analysis**:
- **Option 1: Nitrosodimethylamine** - This compound is known to be carcinogenic but is not found in coal tar. Therefore, this option is incorrect.
- **Option 2: 3-4 Benzopyrene** - This is a well-known carcinogen that is indeed present in coal tar and is responsible for its cancer-causing properties. This option is correct.
- **Option 3: 2-Naphthylamine** - Although this compound is carcinogenic, it is primarily found in cigarette smoke, not in coal tar. Thus, this option is incorrect.
- **Option 4: 4-Aminobiphenyl** - This compound is also carcinogenic and is found in tobacco products, not in coal tar. Hence, this option is incorrect.

5. **Conclusion**:
- After evaluating all the options, the only carcinogen present in coal tar is **3-4 Benzopyrene**. Therefore, the correct answer to the question is Option 2.

### Final Answer:
The carcinogen present in coal tar is **3-4 Benzopyrene**.