CBSE 2026 · Region 5 · Set 1 · Q28 · 3 marks
(a)Arrange the following compounds in increasing order of their acidic strengths :
(ii)Why is $\displaystyle \mathrm{CH}_{3} \mathrm{CHO}$ more reactive than acetone towards reaction with HCN ?(iii)Complete the equation :An organic compound with the molecular formula $\displaystyle \mathrm{C}_{8} \mathrm{H}_{8} \mathrm{O}$ forms $\displaystyle 2,4$-DNP derivative, reduces Tollens' reagent and undergoes Cannizzaro reaction. On vigorous oxidation it gives Benzene-$\displaystyle 1,2$-dicarboxylic acid. Identify the compound and write the reactions of compound $\displaystyle 2,4$-DNP and when it undergoes Cannizzaro reaction.
(a)
Arrange the following compounds in increasing order of their acidic strengths :
(ii)
Why is $\displaystyle \mathrm{CH}_{3} \mathrm{CHO}$ more reactive than acetone towards reaction with HCN ?
(iii)
Complete the equation :
An organic compound with the molecular formula $\displaystyle \mathrm{C}_{8} \mathrm{H}_{8} \mathrm{O}$ forms $\displaystyle 2,4$-DNP derivative, reduces Tollens' reagent and undergoes Cannizzaro reaction. On vigorous oxidation it gives Benzene-$\displaystyle 1,2$-dicarboxylic acid. Identify the compound and write the reactions of compound $\displaystyle 2,4$-DNP and when it undergoes Cannizzaro reaction.
Marking-scheme solution
(a)
(ii)
Due to steric hindrance and electronic effect / The presence of two methyl
groups in acetone hinders the approach of nucleophile to carbonyl carbon than in
ethanal having one methyl group.
(iii)
Aldehydes, Ketones and Carboxylic AcidsChemical Reactions of Aldehydes, Ketones and Carboxylic AcidsApplyshort_answermedium
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CBSE Class 12 Chemistry past-paper question from the 2026board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.