Read the passage carefully and answer the following questions.

Aldehydes, carboxylic acids and ketones are widespread in the animal and plant kingdoms. They play a pivotal role in various biochemical processes of life. Their presence in nature adds fragrance and flavor. These compounds are widely used in food products, pharmaceuticals, paints, resins and other important product industries. These compounds are prepared by various laboratory methods, which mainly include oxidation, formylation, acylation and reduction. Due to the polar nature of the carbonyl group in aldehydes and ketones, they can exhibit different reactions like nucleophilic addition. They do exhibit redox and various condensation reactions which lead to the formation of various important compounds. On the other hand, the carboxylic acids are mainly prepared by oxidation and hydrolysis of different compounds. The carboxylic acid consists of a carbonyl group and the hydroxy group (attached to the carbonyl carbon atom). This makes it possible for the carboxylic acid to participate in various chemical reactions which involve cleavage of the C-OH bond and the O-H bond along with the reactions involving the complete -COOH group.

Which of the following compounds will give butanone on oxidation with chromic anhydride ($CrO_3$)?

Butan-2-ol

The correct answer is Option (2) → Butan-2-ol
• Chromic anhydride (CrO₃) is a strong oxidising agent.
• Secondary alcohols oxidise to ketones.
• Butan-2-ol is a secondary alcohol, so it oxidises to butanone (a ketone).

Why others are incorrect:
• Butan-1-ol is a primary alcohol → oxidises to butanal and then butanoic acid, not butanone.
• 2-Methyl propane and 2-Methyl butane are alkanes → alkanes generally do not oxidise with CrO₃ under normal conditions.