Some Basic Concepts of Organic Chemistry
109 Questions
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2017
Q51
NEET
MCQ
10 Mar 2026
The correct statement regarding electrophile is
A.
electrophile is a negatively charged species and form a bond by accepting a pair of electrons from another electrophile
B.
electrophiles are generally neutral species and can form a bond by accepting a pair of electrons from a nucleophile
C.
electrophile can be either neutral or positively charged species and can form a bond by accepting a pair of electrons from a nucleophile
D.
electrophile is a negatively charged species and can form a bond by accepting a pair of electrons from a nucleophile.
2017
Q52
NEET
MCQ
10 Mar 2026
The most suitable method of separation of 1 : 1 mixture of ortho and para-nitrophenols is
A.
chromatography
B.
crystallisation
C.
steam distillation
D.
sublimation.
2017
Q53
NEET
MCQ
10 Mar 2026
The IUPAC name of the compound
A.
5-formylhex-2-en-3-one
B.
5-methyl-4-oxohex-2-en-5-al
C.
3-keto-2-methylhex-5-enal
D.
3-keto-2-methylhex-4-enal
2016
Q54
NEET
MCQ
10 Mar 2026
Which among the given molecules can exhibit tautomerism?
A.
III only
B.
Both I and III
C.
Both I and II
D.
Both II and III
2016
Q55
NEET
MCQ
10 Mar 2026
The correct statement regarding the comparison of staggered and eclipsed conformations of ethane, is
A.
the eclipsed conformation of ethane is more stable than staggered conformation even through the eclipsed conformation has torsional strain
B.
the staggered conformation of ethane is more stable than eclipsed conformation, because staggered conformation has no torsional strain
C.
the staggered conformation of ethane is less stable than eclipsed conformation, because staggered conformation has torsional strain
D.
the eclipsed conformation of ethane is more stable than stggered conformation, because eclipsed conformation has no torsional strain.
2015
Q56
NEET
MCQ
10 Mar 2026
Which of the following statements is not correct for a nucleophile?
A.
Ammonia is a nucleophile.
B.
Nucleophiles attack low e$-$ density sites.
C.
Nucleophiles are not electron seeking.
D.
Nucleophile is a Lewis acid.
2015
Q57
NEET
MCQ
10 Mar 2026
The possible stereo-structures of CH3CHOHCOOH, which are optically active, are called
A.
atropisomers
B.
enantiomers
C.
mesomers
D.
diastereomers
They are enantiomers (non-superimposable
mirror images)
2015
Q58
NEET
MCQ
10 Mar 2026
Given :
Which of the given compounds can exhibit tautomerism?
Which of the given compounds can exhibit tautomerism?
A.
II and III
B.
I, II and III
C.
I and II
D.
I and III
2015
Q59
NEET
MCQ
10 Mar 2026
The total number of $\pi $-bond electrons in the following structure is
A.
12
B.
16
C.
4
D.
8
2015
Q60
NEET
MCQ
10 Mar 2026
Which of the following is the most correct electron displacement for a nucleophilic reaction to take place?
A.
B.
C.
D.
2015
Q61
NEET
MCQ
10 Mar 2026
Consider the following compounds :
Hyperconjunction occurs in
Hyperconjunction occurs in
A.
III only
B.
I and III
C.
I only
D.
II only
2015
Q62
NEET
MCQ
10 Mar 2026
The enolic form of ethyl accetoacetate as shown below has
A.
9 sigma bonds and 2 pi-bonds
B.
9 sigma bonds and 1 pi-bond
C.
18 sigma bonds and 2 pi-bonds
D.
16 sigma bonds and 1 pi-bond.
2015
Q63
NEET
MCQ
10 Mar 2026
In which of the following compounds, the C$-$Cl bond ionisation shall give most stable carbonium ion?
A.
B.
C.
D.
2015
Q64
NEET
MCQ
10 Mar 2026
In Duma's method for estimation of nitrogen, 0.25 g of an organic compound gave 40 mL of nitrogen collected at 300 K temperature and 725 mm pressure. If the aqueous tension at 300 K is 25 mm, the percentage of nitrogen in the compound is
A.
16.75
B.
15.76
C.
17.36
D.
18.20
2014
Q65
NEET
MCQ
10 Mar 2026
In the Kjeldahl's method for estimation of nitrogen present in a soil sample, ammonia evolved from 0.75 g of sample neutralized 10 mL of 1 M H2SO4. The percentage of nitrogen in the soil is
A.
37.33
B.
45.33
C.
35.33
D.
43.33
2013
Q66
NEET
MCQ
10 Mar 2026
What is the hybridisation state of benzyl carbonium ion?
A.
sp2
B.
spd2
C.
sp2d
D.
sp3
2013
Q67
NEET
MCQ
10 Mar 2026
Given :
I and II are
I and II are
A.
identical
B.
a pair of conformers
C.
a pair of geometrical isomers
D.
a pair of optical isomers
2013
Q68
NEET
MCQ
10 Mar 2026
Which of the following chemical system is non aromatic ?
A.
B.
C.
D.
2013
Q69
NEET
MCQ
10 Mar 2026
Arrange the following in increasing order of stability
A.
5 < 4 < 3 < 1< 2
B.
4 < 5 < 3 < 1 < 2
C.
1 < 5 < 4 < 3 < 2
D.
5 < 4 < 3 < 2 < 1
2013
Q70
NEET
MCQ
10 Mar 2026
Homolytic fission of the following alkanes forms free radicals CH3 $-$ CH3, CH3 $-$ CH2 $-$ CH3, (CH3)2CH $-$ CH3, CH3 $-$ CH2 $-$CH(CH3)2.
Increasing order of stability of the radicals is
Increasing order of stability of the radicals is
A.
$\eqalign{
& {\left( {C{H_3}} \right)_2}\mathop C\limits^ \bullet \, - \,C{H_2}C{H_3}\, < C{H_3}\, - \,\mathop C\limits^ \bullet H - \,C{H_3} \cr
& < C{H_3}\, - \,\mathop C\limits^ \bullet {H_2}\, < {\left( {C{H_3}} \right)_3}\mathop C\limits^ \bullet \cr} $
B.
$\eqalign{
& C{H_3}\, - \,\mathop C\limits^ \bullet {H_2}\, < \,C{H_3}\, - \,\mathop C\limits^ \bullet HH\, - \,C{H_3}\, < \cr
& {\left( {C{H_3}} \right)_2}\mathop C\limits^ \bullet \, - \,C{H_2}\, - \,C{H_3}\, < \,{\left( {C{H_3}} \right)_3}\mathop C\limits^ \bullet \cr} $
C.
$\eqalign{
& C{H_3} - \mathop C\limits^ \bullet {H_2} < C{H_3} - \mathop C\limits^ \bullet H - C{H_3} < \cr
& {\left( {C{H_3}} \right)_3}\mathop C\limits^ \bullet \, < {\left( {C{H_3}} \right)_2}\mathop C\limits^ \bullet \, - C{H_2}C{H_3} \cr} $
D.
$\eqalign{
& {\left( {C{H_3}} \right)_3}\mathop C\limits^ \bullet \, < {\left( {C{H_3}} \right)_2}\mathop C\limits^ \bullet \, - C{H_2}C{H_3} < \cr
& C{H_3} - \mathop C\limits^ \bullet H - C{H_3} < C{H_3} - \mathop C\limits^ \bullet {H_2} \cr} $
2013
Q71
NEET
MCQ
10 Mar 2026
Some meta-directing substituents in aromatic substitution are given. Which one is most deactivating ?
A.
$-$COOH
B.
$-$ NO2
C.
$-$ C $ \equiv $ N
D.
$-$ SO3H
2013
Q72
NEET
MCQ
10 Mar 2026
Structure of the compound whose IUPAC name is 3-Ethyl-2-hydroxy-4-methylhex-3-en-5-ynoic acid is
A.
B.
C.
D.
2013
Q73
NEET
MCQ
10 Mar 2026
The radical,
is aromatic because it has
is aromatic because it has
A.
7 p-orbitals and 7 unpaired electrons
B.
6 p-orbitals and 7 unpaired electrons
C.
6 p-orbitals and 6 unpaired electrons
D.
7 p-orbitals and 6 unpaired electrons.
2013
Q74
NEET
MCQ
10 Mar 2026
The structure of isobutyl group in an organic compound is
A.
B.
C.
D.
2012
Q75
NEET
MCQ
10 Mar 2026
Which nomenclature is not according to IUPAC system?
A.
B.
C.
D.
2012
Q76
NEET
MCQ
10 Mar 2026
Which of the following acids does not exhibit optical isomerism?
A.
Maleic acid
B.
$\alpha $-amino acids
C.
Lactic acid
D.
Tartaric acid
2011
Q77
NEET
MCQ
10 Mar 2026
The IUPAC name of the following compound is
A.
trans-2-chloro-3-iodo-2-pentene
B.
cis-3-iodo-4-chloro-3-pentane
C.
trans-3-iodo-4-chloro-3-pentene
D.
cis-2-chloro -3-iodo-2-pentene.
2011
Q78
NEET
MCQ
10 Mar 2026
Considering the state of hybridization of carbon atoms, find out the molecule among the following which is linear ?
A.
CH3 $-$ CH $=$ CH $-$ CH3
B.
CH3 $-$ C$ \equiv $C $-$ CH3
C.
CH2 $=$ CH $-$ CH2 $-$ C$ \equiv $CH
D.
CH3 $-$ CH2 $-$ CH2 $-$ CH3
has sp
hybridized carbon atoms which has bond angle 180o are attached to sp3
hybridised carbon atoms. So, it is linear.
2011
Q79
NEET
MCQ
10 Mar 2026
Which one of the following is most reactive towards electrophilic reagent?
A.
B.
C.
D.
2011
Q80
NEET
MCQ
10 Mar 2026
The correct IUPAC name for the compound is
A.
4-ethyl-3-propylhex-1-ene
B.
3-ethyl-4-ethenylheptane
C.
3-ethyl-4-propylhex-5-ene
D.
3-(1 -ethylpropyl)hex- 1 -ene.
2010
Q81
NEET
MCQ
10 Mar 2026
Which of the following conformers for ethylene glycol is most stable?
A.
B.
C.
D.
2010
Q82
NEET
MCQ
10 Mar 2026
Which of the following species is not electrophilic in nature?
A.
$\mathop C\limits^ + l$
B.
BH3
C.
H3$\mathop O\limits^ + $
D.
$\mathop N\limits^ + $O2
2010
Q83
NEET
MCQ
10 Mar 2026
The IUPAC name of the compound
CH3CH$=$CHC$ \equiv $CH is
CH3CH$=$CHC$ \equiv $CH is
A.
pent-4-yn-2-ene
B.
pent-3-en-1-yne
C.
pent-2-en-4-yne
D.
pent-1-yn-3-ene
2010
Q84
NEET
MCQ
10 Mar 2026
In the following the most stable conformation of n-butane is
A.
B.
C.
D.
2010
Q85
NEET
MCQ
10 Mar 2026
Which one of the following is most reactive towards electrophilic reagent?
A.
B.
C.
D.
2009
Q86
NEET
MCQ
10 Mar 2026
The IUPAC name of the compound having the formula
CH$ \equiv $C$-$CH$=$CH2 is
CH$ \equiv $C$-$CH$=$CH2 is
A.
1-butyne-3-ene
B.
but-1-yne-3-ene
C.
1-butene-3-yne
D.
3-butene-1-yne.
2008
Q87
NEET
MCQ
10 Mar 2026
Base strength of
is in the order of
is in the order of
A.
(i) > (iii) > (ii)
B.
(i) > (ii) > (iii)
C.
(ii) > (i) > (iii)
D.
(iii) > (ii) > (i)
2008
Q88
NEET
MCQ
10 Mar 2026
The stability of carbanions in the following.
is in the order of
is in the order of
A.
(iv) > (ii) > (iii) > (i)
B.
(i) > (iii) > (ii) > (iv)
C.
(i) > (ii) > (iii) > (iv)
D.
(ii) > (iii) > (iv) > (i)
2008
Q89
NEET
MCQ
10 Mar 2026
How many stereoisomers does this molecule have?
CH3CH$=$CHCH2CHBrCH3
CH3CH$=$CHCH2CHBrCH3
A.
8
B.
2
C.
4
D.
6
2008
Q90
NEET
MCQ
10 Mar 2026
Which one of the following is most reactive towards electrophilic attack?
A.
B.
C.
D.
2007
Q91
NEET
MCQ
10 Mar 2026
For (i) I$-$, (ii) Cl$-$, (iii) Br$-$, the increasing order of nucleophilicity would be
A.
Cl$-$ < Br$-$ < I$-$
B.
I$-$ < Cl$-$ < Br$-$
C.
Br$-$ < Cl$-$ < I$-$
D.
I$-$ < Br$-$ < Cl$-$
2007
Q92
NEET
MCQ
10 Mar 2026
The order of decreasing reactivity towards an electrophilic reagent, for the following would be
(i) benzene
(ii) toluene
(iii) chlorobenzene
(iv) phenol
(i) benzene
(ii) toluene
(iii) chlorobenzene
(iv) phenol
A.
(ii) > (iv) > (i) > (iii)
B.
(iv) > (iii) > (ii) > (i)
C.
(iv) > (ii) > (i) > (iii)
D.
(i) > (ii) > (iii) > (iv)
2007
Q93
NEET
MCQ
10 Mar 2026
If there is no rotation of plane polarised light by a compound in a specific solvent, through to be chiral, it may mean than
A.
the compound is certainly meso
B.
there is no compound in the solvent
C.
the compound may be a racemic mixture
D.
the compound is certainly a chiral.
2006
Q94
NEET
MCQ
10 Mar 2026
The IUPAC name of
is
is
A.
1-chloro-1-oxo-2, 3-dimethylpentane
B.
2-ethyl-3-methylbutanoyl chloride
C.
2, 3-dimethylpentanoyl chloride
D.
3, 4-dimethylpentanoyl chloride.
2005
Q95
NEET
MCQ
10 Mar 2026
The chirality of the compound
A.
R
B.
S
C.
E
D.
Z
2005
Q96
NEET
MCQ
10 Mar 2026
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.
2005
Q97
NEET
MCQ
10 Mar 2026
Which amongst the following is the most stable carbocation?
A.
$\mathop C\limits^ + $H3
B.
CH3$\mathop C\limits^ + $H2
C.
D.
2005
Q98
NEET
MCQ
10 Mar 2026
Names of some compounds are given. Which one is not in IUPAC system?
A.
B.
C.
D.
2005
Q99
NEET
MCQ
10 Mar 2026
The best method for the separation of naphthalene and benzoic acid from their mixture is
A.
distillation
B.
sublimation
C.
chromatography
D.
crystallisation.
2004
Q100
NEET
MCQ
10 Mar 2026
The molecular formula of diphenyl methane,
How many structural isomers are possible when one of the hydrogen is replaced by a chlorine atom ?
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
