Why is sulphuric acid not used during the reaction of alcohols with KI?
In the presence of sulphuric acid (H2SO4), KI produces HI
`2KI + H_2SO_4 -> 2KHSO_4 + 2HI`
Since `H_2SO_4` is an oxidizing agent, it oxidizes HI (produced in the reaction to I2).
`2HI + H_2SO_4 -> I_2 + SO_2 + H_2O`
As a result, the reaction between alcohol and HI to produce alkyl iodide cannot occur. Therefore, sulphuric acid is not used during the reaction of alcohols with KI. Instead, a non-oxidizing acid such as H3PO4 is used.