Substitution reaction

  1. Which one of the following compounds can be made from ethanol using only a substitution

(A) Ethanal
B1 Bromoethane
C) Ethanoic acid
D) Ethoxyethane
E) Ethene

Substitution rection of alcohol means to replace the hydroxyl (-OH) group with some other group.
A) Oxidation of primary alcohol gives aldehydes (ethanal)
B) Substitution of alcohol (-OH group being replaced by -X)
C) Oxidation of aldehyde/ketone gives carboxylic acids (ethanoic acid)
D) Dehydration of alcohol with H2SO4 at 140 °C gives ether (ethoxyethane)
E) Dehydration of alcohol H2SO4 at 170 °C gives alkenes (ethene)


The answer key says A. I do not understand why

ethanol to ethanal is a DIRECT nucleophilic substitution through esterification when reacting with a carboxylic acid.The key word in the question is ONLY substitution.

You may think B is correct however there are two steps, first the protonation of the alcohol and then only bromine can be added.

Bromoethane to ethanol however (the reverse reaction) is a substitution

Does this help?:slight_smile:


I get it now. Thank you