question_answer

Match the following

Column I	Column II
(A) Acetaldehyde, Vinyl alcohol (B) Eclipsed and staggered ethane (C) (+) 2-butanol, (-) 2- butanol (D) Methyl-n- propylamine and diethylamine	1. Enantiomers 2. Tautomers 3. Chain isomers 4. Conformational isomers  5. Metamers

A) A     B      C      D                 1     4      3       5

B)                 2     4      1       5

C)                 5     1      4       2

D)                  5     1      3      2

Correct Answer: B

Solution :

\[\underset{\text{acetaldehyde}}{\mathop{\text{C}{{\text{H}}_{\text{3}}}\text{CHO}}}\,\xrightarrow{\text{Tautomerisation}}\underset{\text{Vinyl alcohol}}{\mathop{\text{C}{{\text{H}}_{\text{2}}}\text{=CH-OH}}}\,\] Thus, these two are tautomers. Eclipsed and staggered ethane are two conformations of ethane. (+) 2-butanol and (-)2-butanol are enantiomers as these are non-superimposable mirror images and  \[\underset{\text{(diethylamine)}}{\mathop{{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}\text{NH}{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}}}\,\] Due to difference in the nature of alkyl groups attached to the same functional group, these are called metamers.