CHEMISTRY(KCET)
285576
Reaction by which benzaldehyde cannot be prepared is
1 Toluene\(\xrightarrow[\text { (ii) } \mathrm{H}_3 \mathrm{O}^{+}]{\text {(i) } \mathrm{CrO}_2 \mathrm{Cl}_2 \mathrm{inCS}_2}\)
2 Benzoyl chloride\(+\mathrm{H}_2 \xrightarrow[\Delta]{\mathrm{Pd}-\mathrm{BaSO}_4}\)
3 Benzene\(+\mathrm{CO}+\mathrm{HCl} \xrightarrow{\text { anhydrous } \mathrm{AlCl}_3}\)
4 Benzoic acid\(\xrightarrow{\mathrm{Zn}-\mathrm{Hg} \text { and conc. } \mathrm{HCl}}\)
Explanation:
(d) \(\mathrm{Zn}-\mathrm{Hg} / \text { conc. } \mathrm{HCl} \text { is used to reduce }