Q.64. Given below are two statements :
Statement-I : 2, 6-diethylcyclohexanone and 6-methyl-2-n-prop

Q: What is the correct answer for JEE Main Chemistry Q64?

The correct answer is C. Statement-I: Metamers are isomers that have the same molecular formula but differ in the nature of alkyl groups attached to the same functional group. Both compounds are cyclohexanones. Let's write their structures and molecular formulas. 2, 6-diethylcyclohexanone: Cyclohexanone ring (C$_6$H$_{10}$O) with two ethyl groups (-C$_2$H$_5$) at positions 2 and 6. Molecular formula: C$_6$H$_{8}$O(C$_2$H$

Q: Q.64. Given below are two statements : Statement-I : 2, 6-diethylcyclohexanone and 6-methyl-2-n-propylcyclohexanone are metamers. Statement-II: 2, 2, 6, 6-tetramethylcyclohexanone exhibits keto-enol…

The correct answer is C. Statement-I: Metamers are isomers that have the same molecular formula but differ in the nature of alkyl groups attached to the same functional group. Both compounds are cyclohexanones. Let's write their structures and molecular formulas. 2, 6-diethylcyclohexanone: Cyclohexanone ring (C$_6$H$_{10}$O) with two ethyl groups (-C$_2$H$_5$) at positions 2 and 6. Molecular formula: C$_6$H$_{8}$O(C$_2$H$

Q: What are the options for this JEE Main Chemistry question?

A. Both Statement-I and Statement-II are true. · B. Both Statement-I and Statement-II are false. · C. Statement-I is true but Statement-II is false. · D. Statement-I is false but Statement-II is true.

Question

Q.64. Given below are two statements :
Statement-I : 2, 6-diethylcyclohexanone and 6-methyl-2-n-propylcyclohexanone are metamers.
Statement-II: 2, 2, 6, 6-tetramethylcyclohexanone exhibits keto-enol tautomerism.
In the light of the above statements, choose the correct answer from the options given below.

FirstInTest · Accepted Answer

Statement-I: Metamers are isomers that have the same molecular formula but differ in the nature of alkyl groups attached to the same functional group. Both compounds are cyclohexanones. Let's write their structures and molecular formulas.
2, 6-diethylcyclohexanone: Cyclohexanone ring (C$_6$H$_{10}$O) with two ethyl groups (-C$_2$H$_5$) at positions 2 and 6. Molecular formula: C$_6$H$_{8}$O(C$_2$H$_5$)$_2$ = C$_6$H$_{8}$O(C$_4$H$_{10}$) = C$_{10}$H$_{18}$O.
6-methyl-2-n-propylcyclohexanone: Cyclohexanone ring (C$_6$H$_{10}$O) with a methyl group (-CH$_3$) at position 6 and an n-propyl group (-C$_3$H$_7$) at position 2. Molecular formula: C$_6$H$_{8}$O(CH$_3$)(C$_3$H$_7$) = C$_6$H$_{8}$O(C$_4$H$_{10}$) = C$_{10}$H$_{18}$O.
Both compounds have the same molecular formula (C$_{10}$H$_{18}$O) and are ketones (cyclohexanone derivatives). They differ in the alkyl groups attached to the carbon atoms adjacent to the carbonyl group (which can be considered part of the functional group environment). In 2,6-diethylcyclohexanone, the groups are two ethyl groups. In 6-methyl-2-n-propylcyclohexanone, the groups are a methyl and an n-propyl group. Thus, they are metamers. So, Statement-I is true.

Statement-II: 2, 2, 6, 6-tetramethylcyclohexanone exhibits keto-enol tautomerism. For keto-enol tautomerism to occur, there must be at least one $\alpha$-hydrogen atom (hydrogen atom on a carbon adjacent to the carbonyl group). In 2, 2, 6, 6-tetramethylcyclohexanone, the carbon atoms at positions 2 and 6 are $\alpha$-carbons. Position 2 has two methyl groups attached, so it has no $\alpha$-hydrogens. Position 6 also has two methyl groups attached, so it has no $\alpha$-hydrogens. Since there are no $\alpha$-hydrogens, this compound cannot exhibit keto-enol tautomerism. So, Statement-II is false.

Therefore, Statement-I is true, and Statement-II is false. This corresponds to option (3).

Answer

Both Statement-I and Statement-II are true.

Answer

Both Statement-I and Statement-II are false.

Answer

Statement-I is true but Statement-II is false.

Answer

Statement-I is false but Statement-II is true.

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