Question

Give a simple chemical test to distinguish between butan-1-ol and butan-2-ol.

Hint:

The oxidation test and iodoform test can help distinguish between primary and secondary alcohols. Primary alcohols are oxidized to carboxylic acids, while secondary alcohols form ketones.

Answer 1

To differentiate butan-1-ol and butan-2-ol, an oxidation test using potassium dichromate (\( K_2Cr_2O_7 \)) in an acidic medium can be performed. Butan-1-ol oxidizes to butanoic acid, whereas butan-2-ol oxidizes to acetone.
Butan-1-ol oxidation yields butanoic acid (a carboxylic acid).
Butan-2-ol oxidation yields acetone (a ketone).
A further test involves reaction with iodine and NaOH:
Both butan-1-ol and butan-2-ol produce a yellow iodoform precipitate when reacted with iodine and NaOH. However, the difference in the intensity of the reaction can be used for differentiation.