Chemistry - Halogen Derivative Question with Solution | TestHub

Question Explanation:  

Identify the incorrect statement among the given orders related to reaction rates, stability, and nucleophilicity.

Concept:

This question is based on 

1. Rate of electrophilic addition, 

2. Rate of SN¹ reaction, 

3. Heat of hydrogenation, 

4. Nucleophilicity in polar protic solvents.

Solution:  

1. In electrophilic addition, alkenes react faster than alkynes; hence CH₂=CH₂ > CH≡CH is correct.

2. SN¹ reaction rate increases with carbocation stability; therefore benzyl < diphenylmethyl < triphenylmethyl bromide is correct.

3. Heat of hydrogenation is higher for alkynes (more number of pi bonds) than alkenes, so HC≡CH > CH₂=CH₂ is correct.

4. In polar protic solvents, nucleophilicity increases down the group due to solvation effects; thus SH^- > OH^- .

Hence the given order SH^- < OH^- is incorrect