Choose the correct statement(s) for intermolecular dehydration of alcohols to form ethers
(A)The formation of ether may involve a nucleophilic bimolecular \( SN^2 \) reaction or \( SN^1 \) reaction
(B) The method is successful with secondary and tertiary alcohols.
(C) The reaction requires protic acids
(D) The reaction is carried out at low temperature.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → (A), (C) and (D) only
Two molecules of a primary alcohol lose one molecule of water between them in the presence of a protic acid, and the temperature decides whether an ether or an alkene is formed:
\( \displaystyle \ce{2C2H5OH} \xrightarrow[\text{413 K}]{\text{conc. }\ce{H2SO4}} \ce{C2H5-O-C2H5 + H2O} \)
(A) The formation of ether may involve a nucleophilic bimolecular \(S_N2\) reaction or \(S_N1\) reaction — Correct. A primary alcohol reacts by \(S_N2\) attack on the protonated alcohol; secondary and tertiary alcohols go through a carbocation (\(S_N1\)).
(B) The method is successful with secondary and tertiary alcohols. — Incorrect. With these alcohols elimination wins and alkenes are formed.
(C) The reaction requires protic acids — Correct. The acid protonates the –OH group so that water can leave.
(D) The reaction is carried out at low temperature. — Correct. At a higher temperature the alcohol gives the alkene instead.
NCERT (2026-27 edition):
By Dehydration of Alcohols
