Which of the following compounds will undergo racemisation when solution of KOH hydrolyses?
A
(i) and (ii)
B
(ii) and (iv)
C
(iv)
D
(i) and (iv)
Explanation
Out of the given four compounds only (iv)
compound is chiral and hence only this
compound will undergo racemisation.
2
NEET 2013 (Karnataka)
MCQ (Single Correct Answer)
Given :
I and II are
A
identical
B
a pair of conformers
C
a pair of geometrical isomers
D
a pair of optical isomers
Explanation
Conformers are form of stereoisomers in
which isomers can be interconverted by rotation
about single bonds. I and II are staggered and
eclipsed conformers respectively.
3
AIPMT 2012 Mains
MCQ (Single Correct Answer)
In the replacement reaction
The reaction will be most favourable if M happens to be
A
Na
B
K
C
Rb
D
Li
Explanation
Tertiary alkyl halides shows SN1
mechanism
to the greater extent. In the given reaction negative
ion will attack on carbocation. Thus, greater the
tendency of ionization (greater ionic character in
M-F bond) more favourable will be reaction. In the
given options Rb-F is most ionic and hence it will be
most favourable for SN1
mechanism.
4
AIPMT 2011 Mains
MCQ (Single Correct Answer)
Consider the reactions.
The mechanisms of reactions (i) and (ii) are respectively
A
SN1 and SN2
B
SN1 and SN1
C
SN2 and SN2
D
SN2 and SN1
Explanation
These reactions are purely SN2
reactions as in
reaction (i) and (ii) there is no rearrangement takes
place (rearrangement occurs in SN1
mechanism).
Simple substitution of nucleophile takes place.
Questions Asked from Haloalkanes and Haloarenes
On those following papers in MCQ (Single Correct Answer)
Number in Brackets after Paper Indicates No. of Questions
