CBSE 2024 · Region 4 · Set 1 · Q33 · 5 marks

(a)

An amide 'A' with molecular formula $\displaystyle \mathrm{C}_{7} \mathrm{H}_{7} \mathrm{ON}$ undergoes Hoffmann Bromamide degradation reaction to give amine 'B'. B' on treatment with nitrous acid at $\displaystyle 273$-$\displaystyle 278$ K form 'C' and on treatment with chloroform and ethanolic potassium hydroxide forms 'D'. 'C' on treatment, with ethanol gives 'E'. Identify 'A', 'B', 'C' 'D' and 'E.' and write the sequence of chemical equations. $\displaystyle 5$

(i)

(1)

What is Hinsberg's reagent ?

(2)

Arrange the following compounds in the increasing order of their basic strength in gaseous phase : $\displaystyle \mathrm{C}_{2} \mathrm{H}_{5} \mathrm{NH}_{2},\left(\mathrm{C}_{2} \mathrm{H}_{5}\right)_{3} \mathrm{~N},\left(\mathrm{C}_{2} \mathrm{H}_{5}\right)_{2} \mathrm{NH}$

(ii)

Give reasons for the following :

(1)

Methyl amine is more basic than aniline.

(2)

Aniline readily reacts with bromine water to give $\displaystyle 2$, $\displaystyle 4$, $\displaystyle 6$- tribromoaniline.

(3)

Primary amines have higher boiling points than tertiary amines. $\displaystyle 2+3$

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CBSE Class 12 Chemistry past-paper question from the 2024board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.