Introduction:
The reaction of alcohols with KI is used to distinguish between primary, secondary, and tertiary alcohols. The reaction involves the conversion of alcohols to alkyl iodides by reacting with KI in the presence of an oxidizing agent.

Why is sulphuric acid not used?
Sulphuric acid is a strong acid, and it can easily protonate alcohols to form alkyl sulfates. The presence of alkyl sulfates can interfere with the reaction of alcohols with KI. Therefore, sulphuric acid is not used during the reaction of alcohols with KI.

Alternative reagents:
There are several alternative reagents that can be used in place of sulphuric acid to facilitate the reaction of alcohols with KI. Some of these reagents include:
- Sodium hydroxide: It is used as a base to deprotonate the alcohol and facilitate the reaction with KI.
- Pyridine: It is used as a base and a solvent to facilitate the reaction of alcohols with KI.
- Acetone: It is used as a solvent to facilitate the reaction of alcohols with KI.

Conclusion:
In conclusion, sulphuric acid is not used during the reaction of alcohols with KI because it can interfere with the reaction by protonating the alcohol to form alkyl sulfates. Instead, alternative reagents such as sodium hydroxide, pyridine, and acetone can be used to facilitate the reaction of alcohols with KI.