1
MCQ (Single Correct Answer)

AIPMT 2005

Which amongst the following is the most stable carbocation?
A
$$\mathop C\limits^ + $$H3
B
CH3$$\mathop C\limits^ + $$H2
C
D

Explanation

3o C is more stable due to the stabilization of the charge by three methyl groups (or inductive effect). It can also be explained on the basis of hyperconjugation.
2
MCQ (Single Correct Answer)

AIPMT 2005

Which of the following undergoes nucleophilic substitution exclusively by SN1 mechanism?
A
Ethyl chloride
B
Isopropyl chloride
C
Chlorobenzene
D
Benzyl chloride

Explanation

SN1 reaction is favoured by heavy groups on the carbon atom attached to halogen i.e

Benzyl > allyl > tertiary > primary > secondary > primary > alkyl halides
3
MCQ (Single Correct Answer)

AIPMT 2005

Which one of the following pairs represents stereoisomerism?
A
Structural isomerism and gemetrical isomerism
B
Optical isomerism and geometrical isomerism
C
Chain isomerism and rotational isomerism
D
Linkage isomerism and geometrical isomerism.

Explanation

Pair of optical isomerism and geometrical isomerism are able to exhibit the phenomenon of stereoisomerism because both type of isomers differ only in their orientation in space.
4
MCQ (Single Correct Answer)

AIPMT 2004

The molecular formula of diphenyl methane,



How many structural isomers are possible when one of the hydrogen is replaced by a chlorine atom ?
A
6
B
4
C
8
D
7

Explanation

Only four structural isomers are possible for diphenyl methane.

EXAM MAP

Joint Entrance Examination

JEE Advanced JEE Main

Medical

NEET

Graduate Aptitude Test in Engineering

GATE CE GATE ECE GATE ME GATE IN GATE EE GATE CSE GATE PI