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What happens when (Give chemical equations): (a) Propanone is treated with and then hydrolysed. (b)…

Chemistry20263 marksReaction
What happens when (Give chemical equations): (a) Propanone is treated with $\text{CH}_3\text{MgBr}$ and then hydrolysed. (b) Formaldehyde undergoes Cannizzaro’s reaction. (c) Acetic acid reacts with $\text{SOCl}_2$ and the main product obtained is reduced with $\text{H}_2$ in the presence of $\text{Pd/BaSO}_4$.

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Official answer key

Equations: $\mathrm{CH_{3}COCH_{3}} + \mathrm{CH_{3}MgBr} \xrightarrow{\text{dry}\text{ }\text{ether}} \mathrm{(CH_{3})_{3}COMgBr}$ $\mathrm{(CH_{3})_{3}COMgBr} + \mathrm{H_{2}O} \xrightarrow{\text{hydrolysis}} \mathrm{(CH_{3})_{3}COH} + \mathrm{Mg(OH)Br}$ $2\mathrm{HCHO} + \mathrm{NaOH} \xrightarrow{\text{conc.}\text{ }\text{NaOH}} \mathrm{HCOONa} + \mathrm{CH_{3}OH}$ $\mathrm{CH_{3}COOH} + \mathrm{SOCl_{2}} \longrightarrow \mathrm{CH_{3}COCl} + \mathrm{SO_{2}} + \mathrm{HCl}$ $\mathrm{CH_{3}COCl} + \mathrm{H_{2}} \xrightarrow{\text{Pd}\text{/}\mathrm{BaSO_{4}}} \mathrm{CH_{3}CHO} + \mathrm{HCl}$

Products: 2-methylpropan-2-ol, sodium formate and methanol, ethanal

(a) Propanone with $\mathrm{CH_3MgBr}$ gives an adduct which on hydrolysis gives 2-methylpropan-2-ol. (b) Formaldehyde, having no $\alpha$-hydrogen, undergoes Cannizzaro's reaction with conc. NaOH. (c) Acetic acid gives acetyl chloride, which is reduced by Rosenmund reduction to acetaldehyde.
Aldehydes and Ketones

From ISC 2026 Specimen Chemistry Paper 1, question 19(i).

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