Number of alkanes obtained on electrolysis of a mixture of and is _________ . [2024]
(3)
Kolbe's electrolysis of gives R-R
Thus electrolysis of mixture of and gives three alkanes: and
The incorrect statement regarding conformations of ethane is: [2024]
Ethane has infinite number of conformations.
The dihedral angle in staggered conformation is 60°.
Eclipsed conformation is the most stable conformation.
The conformations of ethane are inter-convertible to one-another.
(3)
3-Methylhex-2-ene on reaction with HBr in presence of peroxide forms an addition product (A). The number of possible stereoisomers for ‘A’ is ______. [2024]
(4)
Major product (A) has two chiral centres and from mechanism of this reaction it is clear that both R and S configurations are possible at both these chiral centres. Hence A has stereoisomers.
When sec-butylcyclohexane reacts with bromine in the presence of sunlight, the major product is : [2025]
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[IMAGE 110]
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[IMAGE 112]
(4)
In free radical bromination of alkanes, that product is major which is formed by most stable free radical intermediate. Stability of free radicals is 3° > 2° > 1°. Out of two 3° carbons present in sec-butylcyclohexane, carbon forms more stable free radical as it has more number of H atoms.
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The maximum number of RBr producing 2-methylbutane by above sequence of reactions is ______. (Consider the structural isomers only) [2025]
4
1
3
5
(1)
Possible structural isomers of R–Br for RH = 2-methylbutane are obtained by placing Br at any one of the following four places:
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Propane molecule on chlorination under photochemical condition gives two di-chloro products, “x” and “y”. Amongst “x” and “y”, “x” is an optically active molecule. How many tri-chloro products (consider only structural isomers) will be obtained from “x” when it is further treated with chlorine under the photochemical condition. [2025]
3
2
5
4
(1)
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