Number of reagents which can convert pivaldehyde into carboxylic acid or its salt.
(1) conc. $OH^{-}$
(2) $CF_{3} - COOH$
(3) $[Ag (NH_{3})_{2}]^{+} OH^{-}$
(4) $HgCl_{2}$ (aq.)
(5) $CH_{3} - COOH$
(6) $K_{2} Cr_{2} O_{7}, H^{+}, Δ$
(7) $KMnO_{4}, H^{+}, Δ$
(8) Anhydrous $H_{2} CrO_{4}$

Question

Number of reagents which can convert pivaldehyde into carboxylic acid or its salt.

(1) conc. $OH^{-}$

(2) $CF_{3} - COOH$

(3) $[Ag (NH_{3})_{2}]^{+} OH^{-}$

(4) $HgCl_{2}$ (aq.)

(5) $CH_{3} - COOH$

(6) $K_{2} Cr_{2} O_{7}, H^{+}, Δ$

(7) $KMnO_{4}, H^{+}, Δ$

(8) Anhydrous $H_{2} CrO_{4}$

TestHub · Accepted Answer

Pivaldehyde, (CH₃)₃CCHO, lacks α-hydrogens. Therefore, in the presence of concentrated OH⁻, it undergoes a Cannizzaro reaction, forming a pivalate salt. This corresponds to reagent (1).

Tollens' reagent, $[A g (N H_{3})_{2}]^{+} O H^{-}$ , as well as K₂Cr₂O₇/H⁺/Δ and KMnO₄/H⁺/Δ, are strong oxidizing agents that convert aldehydes to pivalic acid. These correspond to reagents (3), (6), and (7).

HgCl₂(aq.) also functions as an oxidizing reagent for aldehydes, converting them into carboxylic acids. This corresponds to reagent (4). Conversely, CF₃COOH, CH₃COOH, and anhydrous H₂CrO₄ do not oxidize pivaldehyde to a carboxylic acid or its salt.

Thus, the correct reagents are (1), (3), (4), (6), and (7).

Chemistry - Carboxylic acid and their Derivatives Question with Solution | TestHub

Doubts & Discussion

JEE Advanced 2027 (Class 12+)