Question - 
            
            
            
            
            Answer - 
            In the presence of sulphuric acid (H2SO4),KI produces HI

Since is an oxidizingagent, it oxidizes HI (produced in the reaction to I2).
 is an oxidizingagent, it oxidizes HI (produced in the reaction to I2).

As a result, the reaction between alcoholand HI to produce alkyl iodide cannot occur. Therefore, sulphuric acid is notused during the reaction of alcohols with KI. Instead, a non-oxidizing acidsuch as H3PO4 is used.