Dehydration of alcohols to form ether is SN2 reaction. The mechanism of dehydration of ethanol involves the following steps.
Step 1 (Protonation) : Initially ethyl alcohol gets protonated in the presence of acid to form ethyl oxonium ion.
Step 2 (SN mechanism) : Protonated alcohol species undergoes a backside attack by second molecule of alcohol is a slow step.
Step 3 (Deprotonation) : Formation of diethyl ether by elimination of proton
