Question

Why is the oxidation of a primary alcohol with a mixture of sodium dichromate and sulphuric acid not a good method for the preparation of corresponding aldehyde?

• A. A mixture of sulphuric acid will not oxidized a primary alcohol
• B. The product will be an alkyl sulphonate, $R–S{O}_{3}H$ mixture of sodium dichromate and sulphuric acid will not oxidize a primary alcohol
• C. The product will be the corresponding ketone
• D. Any aldehyde produced will be oxidized further

Answer 1

The correct option is D Any aldehyde produced will be oxidized further

Primary alcohols can be oxidized to either aldehydes or carboxylic acids depending on the reaction conditions. In the case of the formation of carboxylic acids, the alcohol is first oxidized to an aldehyde which is then oxidized further to the acid.

Primary alcohol $\stackrel{\left[O\right]}{\to }$ aldehyde $\stackrel{\left[O\right]}{\to }$ carboxylic acid

So, any aldehyde produced will be oxidized further during the reaction.