How many of the following reagents can convert $Ph - CHO$ into corresponding $Ph - COO^{⊖}$ or $Ph - COOH$
(a) $KMnO_{4} / H^{\oplus}, Δ$ (b) PCC (c) $MnO_{2}$ (d) $CF_{3} CO_{3} H$
(e) NaOI (f) $Ag_{2} O$ (g) Fehling solution (h) $K_{2} Cr_{2} O_{7} /^{⊖} OH, Δ$
(i) conc. $NaOH, Δ$ (j) $CrO_{3}, H_{2} SO_{4}$

Question

How many of the following reagents can convert $Ph - CHO$ into corresponding $Ph - COO^{⊖}$ or $Ph - COOH$

(a) $KMnO_{4} / H^{\oplus}, Δ$ (b) PCC (c) $MnO_{2}$ (d) $CF_{3} CO_{3} H$

(e) NaOI (f) $Ag_{2} O$ (g) Fehling solution (h) $K_{2} Cr_{2} O_{7} /^{⊖} OH, Δ$

(i) conc. $NaOH, Δ$ (j) $CrO_{3}, H_{2} SO_{4}$

TestHub · Accepted Answer

KMnO₄/H⁺ (a), CF₃CO₃H (d), Ag₂O (f), K₂Cr₂O₇/OH⁻ (h), and CrO₃/H₂SO₄ (j) oxidize PhCHO → PhCOOH/PhCOO⁻.

Conc. NaOH, Δ (i) gives the Cannizzaro reaction, producing PhCOO⁻ and PhCH₂OH.

PCC (b) and MnO₂ (c) do not oxidize benzaldehyde to the acid.

NaOI (e) does not react because benzaldehyde lacks the CH₃CO–/CH₃CH(OH)– group required for the iodoform reaction.

Fehling solution (g) is not reduced by aromatic aldehydes like benzaldehyde.

Therefore, the effective reagents are (a), (d), (f), (h), (i), (j) → Total = 6.

Chemistry - ALCOHOL & ETHER Question with Solution | TestHub