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1

AIPMT 2015

MCQ (Single Correct Answer)
The oxidation of benzene by V2O5 in the presence of air produces
A
maleic anhydride
B
benzoic acid
C
benzaldehyde
D
benzoic anhydride.

Explanation

2

AIPMT 2014

MCQ (Single Correct Answer)
Which one is most reactive towards nucleophilic addition reaction?
A
B
C
D

Explanation

Electron withdrawing (–I, –M) groups are more reactive towards nucleophilic addition reactions. Thus, correct order is :
3

NEET 2013

MCQ (Single Correct Answer)
Reaction by which benzaldehyde cannot be prepared
A
B
C
D

Explanation

4

NEET 2013

MCQ (Single Correct Answer)
The order of stability of the following tautomeric compounds is

A
II > I > III
B
II > III > I
C
I > II > III
D
III > II > I

Explanation

Enolic form predominates in compounds containing two carbonyl groups separated by a –CH2 group. This is due to following two factors.

(i) Presence of conjugation which increases stability.

(ii) Formation of intramolecular hydrogen bond between enolic hydroxyl group and second carbonyl group which leads to stablisation of the molecule.

Hence the correct answer is III > II > I

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