Which one of the following is most reactive towards electrophilic reagent?
A
B
C
D
Explanation
+R effect of -OH group is greater than of -OCH3 group. That is why it is highly reactive towards electrophilic
substitutions.
2
AIPMT 2009
MCQ (Single Correct Answer)
The IUPAC name of the compound having the formula
CH$$ \equiv $$C$$-$$CH$$=$$CH2 is
A
1-butyne-3-ene
B
but-1-yne-3-ene
C
1-butene-3-yne
D
3-butene-1-yne.
Explanation
Since the sum of numbers starting from either side
of the carbon chain turns out to be the same, so
lowest number is given to the C = C end.
3
AIPMT 2008
MCQ (Single Correct Answer)
The stability of carbanions in the following.
is in the order of
A
(iv) > (ii) > (iii) > (i)
B
(i) > (iii) > (ii) > (iv)
C
(i) > (ii) > (iii) > (iv)
D
(ii) > (iii) > (iv) > (i)
Explanation
The carbonion which have more s-character
will be more stable. Thus, the order of stability is :
(i) > (ii) > (iii) > (iv)
4
AIPMT 2008
MCQ (Single Correct Answer)
Which one of the following is most reactive towards electrophilic attack?
A
B
C
D
Explanation
Groups like, –Cl and –NO2
shows –I effect.
–I groups attached to the benzene ring decrease
the electron density in the benzene ring and hence less reactive towards
electrophilic attack.
On the other hand, –OH not only shows –I effect
but also +M effect which predominates the –I
character and electron density is increased in the
benzene ring which facilitates electrophilic attack.
Questions Asked from Some Basic Concepts of Organic Chemistry
On those following papers in MCQ (Single Correct Answer)
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