Match List-I with List-II
|
List-I Reaction |
List-II Type of reaction |
|
(A) Hydrolysis of Ethyl Chloride |
(I) Substitution reaction |
|
(B) 2-Propanol is treated with Conc.Sulphuric acid |
(II) Addition reaction |
|
(C) Reaction of HCN with Acetone |
(III) Degradation reaction |
|
(D) Treatment of acetamide with NaOH and \( Br_2 \) |
(IV) Elimination reaction |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → (A)-(I), (B)-(IV), (C)-(II), (D)-(III)
Organic reactions are classed by what happens to the substrate. In a substitution one atom or group is replaced by another; in an addition two parts add across a multiple bond; in an elimination two atoms or groups are removed from adjacent carbons to form a multiple bond; and in a degradation the carbon chain becomes shorter.
(A) Hydrolysis of Ethyl Chloride — This matches (I) Substitution reaction. The hydroxide ion (or water) replaces the chlorine atom, giving ethanol.
\( \displaystyle \ce{C2H5Cl + KOH(aq) -> C2H5OH + KCl} \)
(B) 2-Propanol is treated with Conc.Sulphuric acid — This matches (IV) Elimination reaction. On heating with the acid, the alcohol loses a molecule of water (the –OH group and an H from the next carbon), giving propene. This is acid-catalysed dehydration.
\( \displaystyle \ce{CH3-CH(OH)-CH3} \xrightarrow[\text{heat}]{\text{conc. }\ce{H2SO4}} \ce{CH3-CH=CH2 + H2O} \)
(C) Reaction of HCN with Acetone — This matches (II) Addition reaction. The cyanide ion attacks the carbonyl carbon and H adds to the oxygen: a nucleophilic addition across C=O, giving acetone cyanohydrin.
\( \displaystyle \ce{(CH3)2C=O + HCN -> (CH3)2C(OH)CN} \)
(D) Treatment of acetamide with NaOH and \(Br_2\) — This matches (III) Degradation reaction. This is the Hofmann bromamide degradation: the amide gives a primary amine with one carbon atom less.
\( \displaystyle \ce{CH3CONH2 + Br2 + 4NaOH -> CH3NH2 + Na2CO3 + 2NaBr + 2H2O} \)
Shortcut: (A)-(I) rules out Option (4). Of the rest, only Option (1) has (B)-(IV).