CBSE Class 12 Chemistry 2017 Outside Delhi Set 1 Solved Paper

Question : 26 of 26

Marks: +1, -0

(a) Write the product (s) in the following reactions:

(iii)

{\CH}_3- {\CH}= {\CH}- {\CN} {─────▸}↖{(\a)\DIBAL-\H}↙{(\b)\H_2\O}

(b) Give simple chemical tests to distinguish between the following pairs of compounds :
(i) Butanal and Butan-2-one
(ii) Benzoic acid and Phenol
OR
(a) Write the reactions involved in the following :
(i) Etard reaction
(ii) Stephen reduction
(b) How will you convert the following in not more than two steps :
(i) Benzoic acid to benzaldehyde
(ii) Acetophenone to benzoic acid
(iii) Ethanoic acid to 2-hydroxyethanoic acid

Solution:

(iii)

{\CH}_3- {\CH}= {\CH}- {\CHO}

(b) (i) Tollen's reagent test : Add ammoniacal solution of silver nitrate (Tollen's reagent) in both the solutions. Butanal gives silver mirror whereas Butan-2-one does not.
(ii) Add neutral

{\FeCl}_3

in both the solutions, phenol forms violet colour but benzoic acid does not.
OR(a) (i) Etard reaction

(ii) Stephen reaction

\; {\RCN}+ {\SnCl}_2+ {\HCl} → {\RCH}

= {\NH} {{───▸}}↖{ {\H}_3 {\O}^{+}} {\RCHO}

\; {\RCN}{─────▸}↖{ (\i) {\SnCl}_2+ {\HCl}}↙{(\ii) {\H}_3 \O^{+}} {\RCHO}

(iii)

{\CH}_3 {\COOH} {{ ───▸}}↖{ {\Cl}_{2 \/ p}} {\CH}_2↙{|}↙{\Cl} {\COOH}

{{ ───▸}}↖{ {\KOH}( {\Aq})} {\CH}_2 ↙{|}↙{\OH} {\COOH}

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