Question

What is the final product X in the following reaction? \[ \mathrm{CH_3CH_2CH_2CHO} \xrightarrow[(2)\ H_3O^+]{(1)\ \text{Ammoniacal AgNO}_3} X \]

• A. \(\mathrm{CH_3CH_2CH_2CH_2NH_2}\)
• B. \(\mathrm{CH_3CH_2CH_2COOH}\)
• C. \(\mathrm{CH_3CH_2CH_2CH_2NO_2}\)
• D. \(\mathrm{CH_3CH_2CH_2CH_3}\)

Hint:

Tollens' reagent converts aldehydes into carboxylic acids after acidification and produces the characteristic silver mirror test.

Answer 1

The Correct Option is B

Concept: Ammoniacal silver nitrate solution is Tollens' reagent. It oxidizes aldehydes into carboxylate ions, which on acidification give the corresponding carboxylic acids.

Step 1: Identify the starting compound.
\[ \mathrm{CH_3CH_2CH_2CHO} \] is butanal.

Step 2: Oxidation by Tollens' reagent.
The aldehyde group is oxidized to a carboxylate ion. \[ \mathrm{CH_3CH_2CH_2CHO} \rightarrow \mathrm{CH_3CH_2CH_2COO^-} \]

Step 3: Acidification.
Upon treatment with hydronium ion, \[ \mathrm{CH_3CH_2CH_2COO^-} \rightarrow \mathrm{CH_3CH_2CH_2COOH} \]

Step 4: Identify the product.
The final product is butanoic acid. \[ \boxed{\mathrm{CH_3CH_2CH_2COOH}} \]