Question

Explain the mechanism of dehydration of ethanol.

Hint:

Dehydration of alcohols follows an E1 mechanism in acid medium, favoring alkene formation.

Answer 1

Step 1: Definition: Dehydration of ethanol is an acid-catalyzed elimination reaction, producing ethene. Step 2: Mechanism: Step 2.1: Protonation of Ethanol: \[ C_2H_5OH + H^+ \rightarrow C_2H_5OH_2^+ \] Step 2.2: Formation of Carbocation: \[ C_2H_5OH_2^+ \rightarrow C_2H_5^+ + H_2O \] Step 2.3: Elimination of Proton: \[ C_2H_5^+ \rightarrow C_2H_4 + H^+ \] Step 3: Overall Reaction: \[ C_2H_5OH \xrightarrow{H_2SO_4} C_2H_4 + H_2O \]