Why is sulphuric acid not used during the reaction of alcohols with KI?



Sulphuric acid is a good oxidising agent. When KI reacts with $H_{2}SO_{4}$, it produces HI. In order to produce alkyl iodides (R—I) , this HI should react with alcohols (R—OH). But this reaction does not take place in this manner as $H_{2}SO_{4}$ oxidises HI to ${ I }_{ 2 }$, which in turn, does not react with alcohol.

Instead of$H_{2}SO_{4}$, $H_{3}PO_{4}$ can be used to produce alkyl iodides.