Match List-I (compound) with List-II (reagent or chemical test)
|
List-I Compound |
List-II Reagent or Chemical test |
|
(A) Phenols |
(I) Tollen's test |
|
(B) Amines |
(II) Neutral \( FeCl_3 \) aq. solution |
|
(C) Aldehydes |
(III) Iodoform Test |
|
(D) Methyl Ketones |
(IV) Hinsberg's Test |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → (A)-(II), (B)-(IV), (C)-(I), (D)-(III)
Each class of compound is identified by a test that responds to its own functional group: the phenolic –OH, the N–H of amines, the easily oxidised –CHO, and the \( \ce{CH3CO-} \) group.
(A) Phenols — This matches (II) Neutral \(FeCl_3\) aq. solution. Phenols give a violet colour (a coloured iron(III) phenoxide complex) with neutral ferric chloride solution; alcohols do not.
(B) Amines — This matches (IV) Hinsberg’s Test. Benzenesulphonyl chloride, \( \ce{C6H5SO2Cl} \), gives with a primary amine a sulphonamide that dissolves in alkali, with a secondary amine one that does not, and does not react with a tertiary amine:
\( \displaystyle \ce{C6H5SO2Cl + RNH2 -> C6H5SO2NHR + HCl} \)
(C) Aldehydes — This matches (I) Tollen’s test. Aldehydes reduce ammoniacal silver nitrate and deposit a silver mirror; ketones do not:
\( \displaystyle \ce{RCHO + 2[Ag(NH3)2]+ + 3OH- -> RCOO- + 2Ag v + 2H2O + 4NH3} \)
(D) Methyl Ketones — This matches (III) Iodoform Test. A \( \ce{CH3CO-} \) group is oxidised by sodium hypoiodite to a carboxylate and yellow iodoform:
\( \displaystyle \ce{RCOCH3 + 3NaOI -> RCOONa + CHI3 v + 2NaOH} \)
Shortcut: (A)-(II) appears in Options (3) and (4); (B)-(IV) then leaves only Option (4).