Assertion. Addition of HI to vinyl chloride produces -chloro-1-todoethane
Reason. HI adds to vinyl chloride against Markovnikov's rule

Options

A. If both assertion and reason are true, and reason is the true explanation of the assertion.
B. If both assertion and reason are true, but reason is not the true explanation of the assertion.
C. If assertion is true, but reason is false.
D. If both assertion and reason are false

Explanation

To solve the question regarding the addition of HI to vinyl chloride and the assertion and reason provided, we can break it down into steps:

### Step-by-Step Solution:

1. **Understanding Vinyl Chloride**:
- Vinyl chloride is an alkene with the formula C2H3Cl, which has a double bond between the two carbon atoms. The structure can be represented as H2C=CHCl.

2. **Addition of HI**:
- When HI is added to vinyl chloride, it undergoes an electrophilic addition reaction. In this reaction, the hydrogen (H) from HI will add to one of the carbon atoms of the double bond, while the iodine (I) will add to the other carbon.

3. **Electrophilic Attack**:
- The double bond (C=C) acts as a nucleophile and attacks the electrophilic hydrogen (H+) from HI. This results in the formation of a carbocation intermediate.
- The more stable carbocation will form, which is determined by the stability of the substituents on the carbon atoms involved.

4. **Carbocation Stability**:
- In this case, the carbocation will form on the carbon that is bonded to chlorine (Cl) because chlorine is electronegative and can stabilize the positive charge through inductive effects and back-bonding.

5. **Nucleophilic Attack by Iodide**:
- After the formation of the carbocation, the iodide ion (I-) will attack the positively charged carbon. This results in the formation of -chloro-1-iodoethane.

6. **Markovnikov's Rule**:
- Markovnikov's rule states that in the addition of HX to an alkene, the hydrogen atom will attach to the carbon with the greater number of hydrogen atoms, while the halide (X) will attach to the carbon with fewer hydrogen atoms.
- In this case, the addition of HI to vinyl chloride does not follow Markovnikov's rule because the iodide ion is adding to the carbon with the chlorine atom, which is not the carbon with more hydrogen atoms.

7. **Conclusion**:
- Therefore, the assertion that the addition of HI to vinyl chloride produces -chloro-1-iodoethane is true, and the reason that HI adds against Markovnikov's rule is also true.

### Final Answer:
- **Assertion**: True. The addition of HI to vinyl chloride produces -chloro-1-iodoethane.
- **Reason**: True. HI adds to vinyl chloride against Markovnikov's rule.