Identify the incorrect statement `//` statement `:`
`(i)` Alkynes are more reactive than alkenes towards electrophilic addiction reaction
`(ii)` Alkynes are less reactive than alkenes towards electrophilic addiction reaction
`(iii)` Alkynes decolourise `Br_(2)` water
`(iv)` Addition of `HBr` to alkenes in presence of peroxide proceeds via Markownikoff's rule

Options

A. `540ml`
B. `135ml`
C. `270 ml`
D. `350 ml`

Explanation

To solve the question, we need to analyze each of the statements provided about alkynes and alkenes and determine which one is incorrect.

### Step-by-Step Solution:

1. **Analyze Statement (i)**:
- "Alkynes are more reactive than alkenes towards electrophilic addition reaction."
- **Explanation**: This statement is correct. Alkynes have a triple bond, which is more reactive than the double bond in alkenes. Therefore, they are indeed more reactive towards electrophilic addition reactions.

2. **Analyze Statement (ii)**:
- "Alkynes are less reactive than alkenes towards electrophilic addition reaction."
- **Explanation**: This statement is incorrect. As established in the previous step, alkynes are more reactive than alkenes due to the presence of a triple bond. Hence, this statement is false.

3. **Analyze Statement (iii)**:
- "Alkynes decolourise Br₂ water."
- **Explanation**: This statement is correct. Alkynes can react with bromine water, leading to decolourisation due to the formation of dibromoalkenes.

4. **Analyze Statement (iv)**:
- "Addition of HBr to alkenes in presence of peroxide proceeds via Markovnikov's rule."
- **Explanation**: This statement is incorrect. The presence of peroxide leads to anti-Markovnikov addition of HBr to alkenes, meaning that the bromine atom will add to the less substituted carbon atom of the alkene.

### Conclusion:
The incorrect statements are:
- Statement (ii): "Alkynes are less reactive than alkenes towards electrophilic addition reaction." (Incorrect)
- Statement (iv): "Addition of HBr to alkenes in presence of peroxide proceeds via Markovnikov's rule." (Incorrect)

### Final Answer:
The incorrect statements are (ii) and (iv).