IIT CHEMISTRY
GOC (ELECTRONIC EFFECT)
Physical & Inorganic
Organic Chemistry
NV Sir
VKP Sir
B.Tech. IIT Delhi
M.Sc. IT-BHU
NUCLEON CHEMISTRY
Be in Equilibrium with JEE
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NUCLEON CHEMISTRY
CLASSES FOR IIT-JEE
GOC (ELECTRONIC EFFECT)
Contents
Topic
Page No.
Theory
01 - 03
Exercise - 1
04 - 12
Exercise - 2
13 - 23
Exercise - 3
24 - 30
ANSWER KEY
31 - 33
Syllabus
IIT-JEE 2016
Name : ____________________________ Contact No. __________________
A - 479 Indra Vihar , Kota
ELECTRONIC EFFECTS AND THEIR APPLICATIONS
ELECTRONIC EFFECTS
Permanent Electronic Effects : Permanent electronic effects are mainly divided into following categories:
(1) Inductive Effect
(2) Mesomeric
(3) Hyperconjugation
(4) Reverse hyperconjugation
Inductive Effect (Polar nature of covalent bonds)
The displacement of an electron (shared) pair along the carbon chain due to the presence of an
electron withdrawing or electron releasing groups in the carbon chain is known as Inductive Effect
(–effect).
 

 C---- C ---- C -- G
 –
(G : functional group)
–
C ---- C ---- C -- G
But the effect is insignificant beyond third carbon atom.
 This effect is transmitted through the chain of  bonds and diminishes. with increasing chain
length.
– I group :
The group which withdraws electrons is known as – I group and its effect is known as – I effect.
– I power of various group & cation.
> –
> –
> – NO2 > – SO2R > – CN > – CHO > – COOH > – F > – Cl > – Br >
– I > – OR > – OH > – C  CH > – NH2 > – C6H5 > – CH = CH2 > – H.
– I power of groups in decreasing order with respect to the reference H
+ I group :
The group which donates or gives electron is known as + I group and effect is known as + I effect.


Alkyl groups, O , CO O are + I groups.
(a) + I power of different type groups and anions :
>
> – C(CH3)3 > – CH (CH3)2 > – CH2 – CH3 > – CH3
> – D > – H
+ I power in decreasing order with reference to H
(b) + I power of same type of alkyl groups :
+ I power  number of C’s in same type of alkyl group
For example
Resonance
When a molecule or ion can be represented by two or more structures which have the same
arrangement of atomic nuclei but differ in distribution of electrons, the phenomenon is called as
Resonance. The various structures are called contributing or resonating structures. None of these
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
Organic Chemistry By
VKP Sir
M.Sc. IT-BHU
ELECTRONIC EFFECT # 1
structures truly represents all the properties of that molecule or ion. The actual structure is a resonance
hybrid of several contributing structures.
In the molecule if resonance is present then mesomeric effect may be present or may not be present.
Resonance generally occurs when there is a conjugation of -bonds (alternate double-single-double
bond arrangement) known as conjugated system.
Conjugate positions of the molecule :
Type of Conjugates
(i) ,  conjugation
(ii)
Positive charge,  conjugation
(iii) Negative charge,  conjugation
(iv)
Odd electron,  conjugation
(v) Lone pair,  conjugation
Mesomeric Effects : This is of following types :
+ M effect (+R) :
C
or
When flow of e– pair (movement) starts from the group (G). It takes place when G has a lone pair or
an extra electron (in ion).
Groups which shows '+ m' effect are :
–
> – NH2 > – NHR > – NR2 > – OH > – OR > – NH  C  R > – O  C  R > –Ph, – CH3 > – F >
||
||
O
O
– Cl > – Br > – I, – N = O.
– M effect (– R) :
–C
C
G
or
When e– pair movement takes place towards G from the molecule.
Groups which can show – m effect are
– NO2 > – C  N > – SO3H > – CHO > C  R
||
O
> C  OH
||
O
Hyperconjugation
When (C – H) sigma electrons are in conjugation to pi bond, this conjugation is known as  (C–H),
 conjugation, excessive conjugation or hyperconjugatioon.
Structural requirement for hyperconjugation:
(A) Compound should have at least one sp 2 -hybrid carbon of either alkene alkyl carbocation or alkyl
free radical.
(B) -carbon with respect to sp 2 hybrid carbon should have at least one hydrogen.
If both these conditions are fulfilled then hyperconjugation will take place in the moelucle.
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
Organic Chemistry By
VKP Sir
M.Sc. IT-BHU
ELECTRONIC EFFECT # 2
(C) Hyperconjugation is of three types :
(i)  (C – H),  conjugation : This type of conjugation occurs in alkenes.
(ii)  (C–H), positive charge conjugation : This type of conjugation occurs in alkyl carbocation.
(iii)  (C–H), odd electron conjugation : This type of conjugation occurs in alkyl free radicals-
Reverse Hyperconjugation :
The phenomenon of hyperconjugation is also observed in the system given below :
X
|
– C– C = C
|
where X - halogen
Application of Electronic Effects :
Stability of Alkenes
Carbon-carbon double bond length in alkenes
Stability of Alkyl Carbocations
Stability of Alkyl free radicals :
Electron releasing (or donating) power of R in alkyl benzene :
Aromaticity :
Aromatic Character : [The Huckel (4n + 2) rule]
The following three rules are useful in predicting whether a particular compound is aromatic or non–aromatic.
1. Aromatic compounds are cyclic and planar.
2. Each atom in an aromatic ring is sp2 or sp hybridised.
3. The cyclic  molecular orbital (formed by overlap of p-orbitals) must contain (4n + 2) electrons, i.e., 2,
6, 10, 14 ........  electrons. Where n = an integer 0, 1, 2, 3,..............
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
Organic Chemistry By
VKP Sir
M.Sc. IT-BHU
ELECTRONIC EFFECT # 3
OBJECTIVE QUESTIONS
1.
In which of the following –NO2 group is not coplanar with phenyl ring ?
CH3
(A)
(B)
(C)
N
O
2.
CH3
N
O
O
5.
6.
N=O
O
O
3
2
1
(C) sp2-sp overlap
(D) sp2–sp2 overlap
In which of the following molecules resonance takes place through out the entire system.
(B)
Bond formation is
(A) Always exothermic
(C) neither exothermic nor endothermic
(C)
(D)
(E)
(B) always endothermic
(D) sometimes exothermic and sometimes endothermic
In which of the following molecules both phenyl rings are not complanar ?
(A)
(B)
(C)
(I) CH3 – CH = O
(ii) CH2 = CH – OH
(iii)
(D)
Among , these , which are canonical structures ?
(A) I and II
(B) I and III
(C) II and III
7.
(D)
CH2  CH  CN
(A)
4.
I
N
O
O
C1–C2 bond of this molecule is formed by
(A) sp2–sp2
(B) sp2–sp3 overlap
3.
I
(D) all
In which of the following molecules, all atoms are not coplanar ?
(A)
(B)
(C)
(D)
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
Organic Chemistry By
VKP Sir
M.Sc. IT-BHU
ELECTRONIC EFFECT # 4
8.
I
CH2 = CH – CH = CH – OCH3
II
CH2  CH  CH  CH  OCH3
III
CH2  CH  CH  CH  OCH3
IV
CH2  CH  CH  CH  OCH3






Among these canonical structures which one is least stable ?
(A)I
(B) II
(C) III
9.
Rank the following compounds in order of decreasing acidity of the indicated hydrogen :
O
O
O
CH3CCH2CH2CCH3
(III)
(B) III > I > II
(I) CH2=CH–CH=CH2
(II) CH2  CH  CH  CH2

(C) I > III > II

Among these which are canonical structures ?
(A) I and II
(B) I and II

O
CH3CCH2CCH3
(II)
(A) I > II > III
11.
O
O
CH3CCH2 CH2CH2CCH3
(I)
10.
(D) IV
(D) III > II > I

(C) II and III
(D) II > I> III
CH2  CH  CH  CH  CH3 is more stable than CH3  CH  C  CH  CH3 because
(I)
(II )
(A) there is resonance in I but not in II
(C) there is hyperconjugation in I but not in II
13.
(D) All of these

I
II
III
Among these canonical structures, the correct order of stability is
(A) I > II > III
(B) III > II> I
(C) I > III> II
12.

(III) CH2  CH  CH  CH2
(B) there is tautomerism in I but not in II
(D) II has more cononical structures than I
For phenol which of the following resonating structure is the most stable ?
OH
OH
(A)
(B)
OH
(C)
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
(D) All have equal stability
Organic Chemistry By
VKP Sir
M.Sc. IT-BHU
ELECTRONIC EFFECT # 5

14.
(I) CH3 – O – CH = CH – CH – CH2


(II) CH3  O  CH  CH  CH  CH2

(III) CH3  O  CH  CH  CH2  CH2
Among these three canonical structures (through more are possible) what would be their relative contribution
in the hybrid :
(A) I > II > III
(B) III > II > I
(C) I > III > II
(D) III > I > II
15.
The most stable resonating structure of folllowing compound is:
(A)
(B)
(C)
(D)
In phenol, -electron density is maximum on
(A) ortho and meta positions
(C) meta and para positions
(B) ortho and para positions
(D) none of these
16.
17.
Among these canonical structures of pyridine, the correct order of stability is
(A) (I =V) > (II = IV ) > III
(B) (II = IV) > (I = V) > III
(C) ( I =V) > III > (II = IV )
(D) III > (II = IV) > ( I = V)
18.
N
N
N
N
N
H
I
H
II
H
III
H
IV
H
V
Among these canonical structure of pyrrole, the correct order of stability is
(A) (III = IV) > (II = V) > I
(B) I > (II = V) > (III = IV)
(C) I > (III = IV) > (II = V)
(D) (II = V) > (III = V) > I
19.
The least stable canonical structure among these in
(A) I
(B) II
(C) III
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
(D) all are equally stable
Organic Chemistry By
VKP Sir
M.Sc. IT-BHU
ELECTRONIC EFFECT # 6
20.
Which of the following compounds has maximum electron density in ring ?
(A)
21.
(B)
(C)
(D)
Rank the following free radicals in order of decreasing stability
(I) C6H5CHC6H5
(II) C 6H 5–CH–CH=CH 2
(III) CH 3–CH–CH 3
(IV) C 6H 5–CH –CH3
(V) CH3CH=CHCH2CH2
(VI) CH3–CH2–C–CH3
CH3
(A) I > II > IV > VI > III > V
(C) I > II > III > IV > V > VI
22.
In which of the following molecules  - electron density in ring is minimum :
(A)
23.
(B)
(C)
(D)
In which of the following molecules  – electron density in ring is maximum :
(A)
24.
(B) VI > V > IV > III > II > I
(D) I > IV > VI > V > II > III
(B)
(C)
(D)
In which of the following pairs, first species is more stable then second ?
O
O
–
(A) CH3CH2O or CH3CO
O
–
O
O
(B) CH3CCHCH2CH or CH3CCHCCH3
O
O
(C) CH3CHCH2CCH3 or CH3CH2CHCCH3
(D)
–
N
O
or
–
N
O
4
25.
O1
3
2
26.
In this molecules, -electron-density is more on
(A) C1 and C3
(B) C2 and C4
(C) C2 and C3
(D) C1 and C4
CH3COOH
CH3COONa
CH3CONH3
I
II
III
Among these compounds, the correct order of resonance energy is
(A) I > II > III
(B) III > II > I
(C) II > III > I
(D) II > I > III
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
Organic Chemistry By
VKP Sir
M.Sc. IT-BHU
ELECTRONIC EFFECT # 7
O
O
O
O
27.
(I)
(II)
(III)
(IV)
Among these compounds, which one has maximum resonance energy ?
(A) I
(B) II
(C) III
(D) IV
1
1
2
28.
1
2
3
2
3
4
3
4
4
These are three canonical structures of naphthalene. Examine them and find correct statement among the
following :
(A) All C – C bonds are of same length
(B) C1–C2 bond is shorter than C2 – C3 bond
(C) C1 – C2 bond is longer than C2 – C3 bond (D) none
29.
Which of the following has longest C – O bond :
O
(A)
O
(B)
O
O
(C)
(D)
CH2
NH2
NH2
NH2
30.
CH2=NH
CHO
I
II
III
Among these compounds, the correct order of C – N length is :
(A) IV > I > II > III
(B) III > I > II > IV
(C) III > II > I > IV
IV
(D) III > I > IV > II
31.
Among the following molecules, the correct order of C – C bond length is
(A) C2H6 > C2H4 > C6H6 > C2H2
(B) C2H6 > C6H6 > C2H4 > C2H2 (C6H6 is benzene)
(C) C2H4 > C2H6 > C2H2 > C6H6
(D) C2H6 > C2H4 > C2H2 > C6H6
32.
In which of the following molecules, resonance structures are equivalent :
(A) HCOO–
33.
34.
(B) CH2=CH–CH=CH2
H–O–CN
H–N=C=O
(Cyanic acid)
(Isocyanic acid)
Loss of proton from these two acids produces
(A) same anion
(B) different anions
(C)
(D)
(C) same cation
(D) different cations
C1 – C2 bond is shortest in
1
(A)
(B)
2
1
CH=CH2
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CH2–CH3
(C)
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(D)
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ELECTRONIC EFFECT # 8
35.
Which of these cyclopropene system is aromatic ?
(A) I
(B) II
(C) III
(D) all of these
Which of these species is anti-aromatic ?
(A) I only
(B) II only
(D) Both II and III
36.
(C) III only
37.
The most stable canonical structure of this molecule is
(A)
38.
(B)
(C)
(D)
Which of following compounds is not aromatic ?
(A)
(B)
(C)
(D)
39.
The most stable canonical structure of this molecule is
(A)
(B)
(C)
(D) All are equally stable
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
Organic Chemistry By
VKP Sir
M.Sc. IT-BHU
ELECTRONIC EFFECT # 9
40.
Which of the following statements would be true about this compounds :
(A) All three C–N bonds are of same length
(B) Cl – N and C3 – N bonds are of same length but shorter than C5 – N bond
(C) Cl – N and C3 – N bonds are of same length but longer than C5 – N bond
(D) Cl – N and C3 – N bonds are of different length but both are longer than C5 – N bond
41.
Ease of ionization to produce carbocation and bromide ion under the treatment of Agwill be maximum in
which of the following compounds ?
(A)
42.
(B)
(C)
(D)
Ease of ionization to produe carbocation and bromide ion under the treatment of Ag  will be
maximum in which of the following compounds ?
(A)
43.
(B)
(C)
(D)
P will be
(A)
44.
(B)
2SbCl6–
(C)
(D) Mixture of (a) and (b)
P will be
(A)
(B)
(C) mixture of (A) and (B)
(D) none of these
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
Organic Chemistry By
VKP Sir
M.Sc. IT-BHU
ELECTRONIC EFFECT # 10
45.
The barrier for roatation about the indicated bonds will be maximum in which of these three compounds ?
(A) I
(B) II
(C) III
(D) same in all
46.
I
II
III
The aromatic character is maximum in which of these three compounds ?
(A) I
(B) II
(C) III
(D) same in all
47.
Find out the hybridisation sate of carbon atoms in given compound from left to right.
CH3 – CH = CH – CH = C = CH – C  C – CH3
3
(A) sp sp2 sp2 sp2 sp sp2 sp sp sp3
(B) sp3 sp2 sp2 sp sp sp sp sp sp3
(C) sp3 sp2 sp2 sp2 sp2 sp2 sp sp sp3
(D) sp3 sp sp sp2 sp sp2 sp sp sp3
48.
Total number of  and  bonds are in naphthalene is :
(A) 5 and 18
(B) 6 and 19
(C) 5 and 19
49.
Write correct order of stability of following carbocations :
I
(A) I > II > III > IV
50.
II
(B) III > II > I > IV
III
(C) III > I > II > IV
IV
(D) III > II > IV > I
The abstraction of proton will be fastest, in which carbon in the following compound
(A) x
51.
(D) 7 and 26 
(B) y
Number of p-electron in (C4H4)2– is
(A) 2
(B) 4
(C) z
(D) p
(C) 6
(D) 8
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Organic Chemistry By
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ELECTRONIC EFFECT # 11
52.
Identify the odd species out (Which of the species among the following is different from others ?
(A)
53.
(B)
(II)
(A) III > II > IV > I
(B) I > II > III > IV
(III)
(IV)
(C) III > I > II IV
(D) III > II > I > IV
The order of the rate of formation of carbocations from the following iodo compounds is :
(A) I > II > III
55.
(D)
Correct order of rate of hydrolysis or rate of reaction toward AgNO3 for following compounds is
(I)
54.
(C)
(B) I > III > II
(C) III > II > I
(D) II > III > I
Which one of the following statements is True :
(A) PhLi adds to both compound with equal ease
(B) PhLi does not add to either of the compound
(C) PhLi react readily with 1 but does not add to 2
(D) PhLi react readily with 2 but does not add to 1
56.
Which one of the following carbonyl compound when treated with dilute acid forms the more stable
carbocations ?
(A)
(B)
(C)
Physical & Inorganic By
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(D)
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ELECTRONIC EFFECT # 12
SUBJECTIVE QUESTIONS
1.
2.
In which of the following molecules reasonance takes place through out the entire system.
(A) CH3CH2NHCH2CH=CH2
(B)
(C)
(E)
(F)
(G)
(H)
(I)
(D) CH2=CHCH2CH=CH2
Which of the following pairs of structures are resonance contributors ?

(A)

(B) CH3 CH  CH CH CH  CH2 and CH3 CH CH  CHCH  CH2
(C)
(D)


(E) CH3 C HCH  CHCH3 and CH3CH  CHCH2 C H2
3.
In each of the following pairs, determine whether the two represent resonance forms of a single species or
depict different substances. If two structures are not resonance forms, explain why.
(a)
(b)
(c)
4.
Consider structural formulas A, B and C :
(a) Are A, B and C constitutional isomers, or are they resonance forms ?
(b) Which structures have a negatively charged carbon ?
(c) Which structures have a positively charged carbon ?
(d) Which structures have a positively charged nitrogen?
(e) Which structures have a negatively charged nitrogen?
(f) Which is the net charge on each structure ?
(g) Which is a more stable structure, A or B ? Why ?
(h) Which is a more stable structure, B or C ? Why ?
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
Organic Chemistry By
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M.Sc. IT-BHU
ELECTRONIC EFFECT # 13
5.
Determine the hybridization around the indicated atom in the following anion.
(A)
(B)
(C)
(D)
6.
Using hybridization, predict how the bond length of the C – C  bond in HC CH Should compare with the
C–C s bonds in CH3 CH3 and CH2 =CH – CH = CH2 .
7.
In each of the following pairs of ions which ion is more stable :

8.



(a) (i) C6H5– CH 2 and (ii) CH2=CH– CH 2
(b) (i) CH3– CH 2 and (ii) CH2= CH
(c)
(d) (i)
and (ii)
and (ii)
Draw the resonance forms of show thedelocalization of charges in the following ions
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)


(i) CH3–CH=CH–CH= CH– C H –CH3
(j) CH3–CH=CH–CH=CH– C H2

9.
(k) CH2=CH– C H –CH=CH3
(l)
(m)
(n)
Draw a second resonace structure and the hybrid for each species, and then rank the two resonance
structures and the hybrid in order of increasing stability.

(A) (CH3 )2 C NH2
(B)
Physical & Inorganic By
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ELECTRONIC EFFECT # 14
10.
In the following sets of resonance forms, label the major and minor contributors and state which structure
would be of equal energy. Add any missing resonance forms.
(a)
(b)
(c)
(d)
(e)
11.
For acetic acid (CH3CO2H) : (a) Draw three resonance structures; (b) draw a structure of the resonance
hybrid ; (c) rank the three resonance structures and the resonance hybrid in order of increasing energy.
12.
Use resonance theory to explain why both C – O bond lengths are equal in the acetate anion.
13.
From each set of resonance structures below designate the one that would contribute most to the hybrid
and explain your choice.
(a)
(b)
(c)
(d)
(e)
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
Organic Chemistry By
VKP Sir
M.Sc. IT-BHU
ELECTRONIC EFFECT # 15
14.
Identity more stable canonical structure in each of the following pairs :
(a)
(b)
(c)
(d)
15.
(e)
Identify less stable canonical structure in each of the following pairs :
(a)
(b)
(c)
(d)
(e)
16.
Which of the following statements is (are) true about resonance.
(a) Resonance is an intramolecular process.
(b) Resonance involves delocalization of both  and  electrons.
(c) Resonance involves delocalization of  electrons and lone pair only.
(d) Resonance decreases potential energy of a molecule.
(e) Resonnance has no effect on the potential energy of a molecule.
(f) Resonance is the only way to increase molecular stablility.
(g) Resonance is not the only way to increase molecular stability.
(h) Any resonating molecule is always more stable than any nonresonating molecule.
(i) The canonical structure explains all features of a molecule.
(j) The resonance hybrid explains all feartures of a molecule.
(k) Resonating structures are real and resonance hybrid is imaginary.
(l) Resonance hybrid is real and resonating structures are imaginary.
(m) Resonance hybrid is always more stable than all canonical structures.
17.
Resonance energy will be more if.
(a) Canonical structures are equivalent than if canonical structures are non- equivalent.
(b) molecule is aromatic than molecules is not aromatic.
18.
Which is less stable in each of the following pair :
(a) (I) CO23 – and (II)HCOO–
(b) (I)
(c) (I)
(d) (I)
and (II )CH2 = CH – CH = CH2
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
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and (II)CH2 = CH – CH 2–

and (II) CH2 = CH – C H2
Organic Chemistry By
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M.Sc. IT-BHU
ELECTRONIC EFFECT # 16
19.
A canonical structure will be more stable if
(a) It has more number of bonds than if it has less number of  bonds.
(b) the octets of all atoms are complete than if octets of all atoms not complete.
(c) it nvolves cyclic delocalization of (4n +2)  - electrons than if it involves acyclic delocalization of (4n + 2)
 - electrons.
(d) It involves cyclic delocalization (4n)  - electrons than if it involves acyclic delocalization of (4n)
-electrons.
(e) + ve charge is on more electronegative than if + ve charge is on less electronegative atoms.
(f) – ve charge is on more electronegative than if – ve charge is on less electronegative atoms.
20.
Which of the follwing pairs has higher resonance energy :
(b) CH2 = CH – O and CH2 = CH – OH
(c)
(d)
(e)
21.

(a) CH3COOH and CH3 COONa
and
and
and CH2 = CH – CH = CH – CH = CH2
Which of the following pairs has high higher resonance energy :
(a)
(b)
(c)
(d) CH2 = CH – OH and CH2 = CH – CH = CH – OH
(e)
22.
Rank the following sets of intermidiates in increasing order of their stability giving appropriate reasons for
your choice
(a) C6H5 ,p  NO2 (C6H4 ) ,p  CH3  (C6H4 ) ,p  Cl  C6H4
(b)
23.
Which of the following pairs has less resonance energy :
(a)
(b)
(c)
(d)
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
Organic Chemistry By
VKP Sir
M.Sc. IT-BHU
ELECTRONIC EFFECT # 17
24.
Which of the following pairs has higher resonance energy :
(a)
(b) CH2=CH–O–CH = CH2 and CH2=CH–NH–CH=CH2



(c) CH2  CH  NH and HN  CH  NH
25.
and CH2  CH  CH2
Explain why each compound in aromatic, antiaromatic or nonaromatic.
(a)
26.
(d)
(b)
(c)
(d)
Ordinarily the barrier to rotation about a carbon double bond is quite high but compound A have a rotational
barrier of only about 20 K cal / mol
What is the reason for this ?
27.
Compare the C–N bond length in the following species :
(i)
28.
(ii)
Which is more acidic and why ?
(A)
29.
(iii)
(B)
Squaric acid
is a diprotic acid with both protons being more acidic than acetic acid. In the
di-anion after the loss of both protons all of the C–C bonds are the same length as well as all of the C–O
bonds. Provides a explanation for these observations.
30.
Match each alkene with the appropriate heat of combustion :
Heats of combustion (kJ/mol) : 5293, 4658, 4650, 4638, 4632
(a) 1-Heptene
(b) 2,4-Dimethyl-1-pentene
(d) 4,4-Dimethyl-2-pentene
(e) 2,4,4-Trimethyl-2-pentene
Physical & Inorganic By
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B.Tech. IIT Delhi
A-479 Indra vihar, kota
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(c) 2,4-Dimethyl-2-pentene
Organic Chemistry By
VKP Sir
M.Sc. IT-BHU
ELECTRONIC EFFECT # 18
31.
Choose the more stable alkene in each of the following pairs . Explain your reasoning
(a) 1-Methylcyclohexene or 3- methylcyclohexene
(b) lsopropenylcyclopentane or allylcyclopentane
(c)
32.
or
Consider the given reaction :
Pd / C
+ 3H2 

In the above reaction which one of the given ring will undergo reduction ?
33.
34.
(a)
(I) Stability order and (II) heat of hydrogenation orders.
(A) (i)
(ii)
(iii)
(B) (i)
(ii)
(iii)
(iv)
Compare heat of hydrogenation (Decreasing order)
heat of hydrogenation
(i)
(ii)
(b)
(c)
(d)
(e)
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
Organic Chemistry By
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M.Sc. IT-BHU
ELECTRONIC EFFECT # 19
35.
Among the following pairs identify the one which gives higher heat of hydrogenation :
(a)
(b)
(c) CH3–CH=CH–CH3 and CH3–CH2–CH=CH2
(d)
36.
Discuss the following observations :
(a) C–Cl bond in vinyl chloride is stronger than in chloroethane.
(b) Carbon–carbon bond length in ethene is shorter than in CH2=CHOCH3
(c) CH3SH is stronger acid than CH3OH
(d) CH3CH2NH2 is stronger base than CH2=CHNH2
37.
Write stability order of following intermediates :


(i)
(a) CH3 – C H2
(b) CH3 – C H –CH3
(c)
(ii)
(a)
(b)
(c)
(iii)
(a)
(b)
(c)
(iv)
(a)
(b)
(c)
(v)
(a)
(b)
(c)
(vi)
(a)
(b)
(c)
(vii)
(a) CH3 – C H2
(b) CH3 – C H – CH3
(c)
(viii)
(a)
(b)
(c)


Physical & Inorganic By
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B.Tech. IIT Delhi
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
Organic Chemistry By
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M.Sc. IT-BHU
ELECTRONIC EFFECT # 20
(ix)
(a)
(b)
(c)
(x)
(a)
(b)
(c)
(xi)
(a) HC  C
(xii)
(a) HC  C



38.

(b) CH2 = C H
(c) CH3 – C H2


(b) CH2 = C H
(c) CH3 – C H2
Write stability order of following intermediates :
(i)
(a)
(b)
(c)
(ii)
(a)
(b)
(c)
(iii)
(a)
(b)
(c)
(iv)
(a)
(b)
(v)
(a)
(b) C H – CH
2
3
(vi)
(a)
(b)
(c)
(vii)
(a)
(b)
(c)
(xi)
(a)
(b)

Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
(d)
A-479 Indra vihar, kota
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Organic Chemistry By
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M.Sc. IT-BHU
ELECTRONIC EFFECT # 21
(x)
(a)
(b)
(xi)
(a)
(b)
(c)
(xii)
(a)
(b)
(c)
(xiii)
(a)
(b)
(c)
39.
Arrange in order of C–H bond energy
40.
Write increasing order of heat of hydrogenation :
(c)
(d)
(d)
(i) (a)
(b)
(ii) (a)
(b)
(c)
(d)
(iii) (a)
(b)
(c)
(d)
(iv) (a)
(b)
(c)
(v) (a)
(b)
(c)
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
(e)
(HOH per  bond)
Organic Chemistry By
VKP Sir
M.Sc. IT-BHU
ELECTRONIC EFFECT # 22
(vi) (a)
(b)
(vii) (a)
(viii) (a)
41.
42.
(c)
(HOH per benzene ring)
(b)
(b)
Give decreasing order of heat of combustion (HOC) :
(i) (a)
(b)
(c)
(ii) (a)
(b)
(c)
(iii) (a)
(b)
(iv) (a)
(b)
(d)
(c)
(A) Which compound has the greater electron density on its nitrogen atom ?
(B) Which compound has the greater electron density on its oxygen atom ?
43.
How many grams of H2 released when 46 g of sodium is treated with excess of ethyl alcohol.
44.
Use the following data to answer the questions below :
H = –28.6 Kcal mol–1
H = –116.2 Kcal mol–1
Calculate the resonance energy of anthracene in kcal / mol.
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
Organic Chemistry By
VKP Sir
M.Sc. IT-BHU
ELECTRONIC EFFECT # 23
MATCH THE FOLLOWING
1.
Match the Column :


(a) CH3O C H2 or CH3 NH C H2

3.

(b) CH3 OCH2 C H2 or CH3O C H2
(Q) Second is more stable then first
(c)
(R) Not resonating structure of each other
or
(d)
2.
(P) First is more stable then second
or
(S) Resonance is present in both carbocation
Match the column :
Column - I
Column - II
(a)
(P)
Non aromatic
(b)
(Q)
Anit aromatic
(c)
(R)
Resonance
(d)
(S)
Aromatic
Match the column :
Column - I
Column - II
(a)
(P)
Hybrid state of each atom sp2
(b)
(Q)
Anit aromatic
(c)
(R)
Delocalisation of  bond
(d)
(S)
Non aromatic
(T)
Obeys Huckel’s Rule for aromaticity
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
Organic Chemistry By
VKP Sir
M.Sc. IT-BHU
ELECTRONIC EFFECT # 24
4.
Match the column :
Column- I
Column- II
(a)
(P) Six  electrons
(b)
(Q) Four  electrons
(c)
(R) Aromatic compound
(D)
(S) Anti-aromatic compound
IIT-JEE PROBLEMS (PREVIOUS YEARS)
* Marked Questions are having more than one correct option.
1.
The central carbon-carbon bond in 1, 3-butadiene is shorter than that of n-butane. Why ? [JEE-98]
2.
CH2 = CH¯ is more basic than HC  C¯. Explain.
3.
Which of the following acids has the lowest value of acid dissociation constant :
[JEE-02(S), 3/90]
(A) CH3CHFCOOH
(B) FCH2CH2COOH
(C) BrCH2CH2COOH
(D) CH3CHBrCOOH
4.
Match the Ka values :
5.
Write resonating structure of the compound
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
[JEE-2K(M), 1/100]
[JEE-03(M), 2/60]
.
[JEE-03(S), 2/60]
Organic Chemistry By
VKP Sir
M.Sc. IT-BHU
ELECTRONIC EFFECT # 25
6.
Which of the following represent the given mode of hybridisation sp2 – sp2 – sp – sp from left to right.
[JEE-03(S), 3/84]
(A) H2C = CH – C  N
(B) HC  C – C  CH
7.
A , The product A will be -
(A)
8.
(C) H2C = C = C = CH2 (D)
(B)
[JEE-03(S), 3/84]
(C)
(D)
What is the acidity order of x, y & z ?
(A) x > y > z
[JEE-04(S), 3/84]
(B) x > z > y
(C) y > z > x
(D) z > y > x
Excess of CH COONa
9.
[JEE-05(S), 3/84]
3
     
  
The products will be :
(A) + CH3COONa
(B)
(C)
10.
+ CH3COOH
+ CH3COOH
(D)
+ SO3
Which will be the least stable resonating structure :
[JEE-05(S), 3/84]

(A) CH2 = CH –
–
– O – CH3
(B) C H 2 –
– CH = CH – OCH3

(C)
C H2 –
CH = CH – CH =
NaHCO
11.
3
  

– CH3
(D) CH2 = CH –
;
NaHCO
– CH =
3
  

– CH3
[JEE-06, 3/184]
A mixture of benzene sulphonic acid and paranitrophenol react with NaHCO3 separately. The gases produced
are respectively.
(A) SO2, CO2
(B) SO2, CO
(C) SO2, NO2
(D) CO2, CO2
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
Organic Chemistry By
VKP Sir
M.Sc. IT-BHU
ELECTRONIC EFFECT # 26
12.
Among the following, the least stable resonating structure is :

(A)
(B)
+
+
N

O
(C)
+
14.
Hyperconjugation involves overlap of the following orbitals
(A) –
(B) –p
(C) p – p
15.
The correct stability order for the following species is :
16.
19.
[JEE-2009, 3/160]
(B) 2-Bromo-5-hydroxybenzonitrile
(D) 6-Bromo-3-hydroxybenzonitrile
[JEE-09, 3/160]
(B) (IV) > (III) > (I) > (II)
(D) (II) > (III) > (IV) > (I)
Physical & Inorganic By
B.Tech. IIT Delhi
[JEE-09, 3/160]
(B) (I) > (III) > (II) > (IV)
(D) (III) > (I) > (IV) > (II)
The total number of basic groups in the following form of lysine is :
NV Sir
[JEE-08, 3/163]
(D)  – 
(B) (I) > (II) > (III) > (IV)
(D) (I) > (III) > (II) > (IV)
The correct acidity order of the following is :
(A) (III) > (IV) > (II) > (I)
(C) (III) > (II) > (I) > (IV)
(D)
[JEE-08, 3/163]
The correct stability order of the following resonating structures is :
(A) (I) > (II) > (IV) > (III)
(C) (II) > (I) > (III) > (IV)
18.
O
The IUPAC name of the following compound is :
(A) 4-Bromo-3-cyanophenol
(C) 2-Cyano-4-hydroxybromobenzene
17.
+
N
O

O

(A) (II) > (IV) > (I) > (III)
(C) (II) > (I) > (IV) > (III)
[JEE-07, 3/162]
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
[JEE-10, 3/163]
Organic Chemistry By
VKP Sir
M.Sc. IT-BHU
ELECTRONIC EFFECT # 27
20.
Among the following compounds, the most acidic is :
(A) p-nitrophenol
(B) p-hydroxybenzoic acid
(C) o-hydroxybenzoic acid
(D) p-toluic acid
21.
The total number of contributing structures showing hyperconjugation (involving C-H bonds) for the following
carbocation is :
[JEE-2011]
22.
Which of the following molecules, in pure form, is (are) unstable at room temperature ? [JEE-12, 3/136]
O
O
(A)
23.
(B)
(C)
[JEE-2011]
(D)
The hyperconjugative stabilities of tert-butyl cation and 2-butene, respectively, are due to : [JEE-2013]
(A) p (empty) and * electron delocalisations.
(B)  and  electron delocalisations.
(C) p (filled) and  electron delocalisations.
(D) p (filled)  and  electron delocalisations.
PART - II : AIEEE PROBLEMS (PREVIOUS YEARS)
24.
In which of the following species is the underlined carbon having sp3 hybridisation ?
[AIEEE 2002]
(1) CH3COOH
(2) CH3CH2OH
(3) CH3COCH3
(4) CH2=CH–CH3.
25.
Which of the following compounds has wrong IUPAC name ?
(1) CH3CH2CH2COOCH2CH3  Ethylbutanoate (2)
(3)
26.
 2–Methyl-3-butanol
 3–Methylbutanal
O
||
(4) CH3–CH–C–CH2–CH3  2–Methyl-3-pentanone
|
CH3
In the following benzyl/allyl system
R – CH = CH2
27.
[AIEEE 2002]
and
(R is alkyl group)
decreasing order of inductive effect is :
(1) (CH3)3 C— > (CH3)2CH— > CH3CH2—
(3) (CH3)2CH— > CH3CH2— > (CH3)3C—
[AIEEE-2002]
(2) CH3CH2— > (CH3)2CH— > (CH3)3C—
(4) (CH3)2C— > CH3CH2— > (CH3)3CH—
The IUPAC name of CH3COCH(CH3)2 is
(1) Isopropylmethyl ketone
(3) 4-Methylisopropyl ketone
(2) 2-Methyl-3-butanone
(4) 3-Methyl-2-butanone.
[AIEEE 2003]
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
Organic Chemistry By
VKP Sir
M.Sc. IT-BHU
ELECTRONIC EFFECT # 28
28.
The correct order of increasing basic nature for the bases NH3, CH3NH2 and (CH3)2NH is : [AIEEE-2003]
(1) CH3NH2 < NH3 < (CH3)2NH
(2) (CH3)2NH < NH3 < CH3NH2
(3) NH3 < CH3NH2 < (CH3)2NH
(4) CH3NH2 < (CH3)2NH < NH3
29.
The IUPAC name of the compounds
is
(1) 3,3-Dimethyl -1-hydroxycyclohexane
(3) 3,3-Dimethyl-1-cyclohexanol
30.
31.
32.
33.
(2) 1,1 -Dimethyl-3-hydroxycyclohexane
(4) 1,1-Dimethyl-3-cyclohexanol
Which one of the following does not have sp2 hybridized carbon ?
(1) Acetone
(2) Acetic acid
(3) Acetonitrile
(4) Acetamide
Among the following acid which has the lowest pKa value ?
(1) CH3CH2COOH
(2) (CH3)2CH – COOH (3) HCOOH
(4) CH3COOH
Amongst the following the most basic compound is
(1) p-Nitroaniline
(2) Acetanilide
(3) Aniline
(4) Benzylamine
[AIEEE 2004]
[AIEEE-2005]
[AIEEE-2005]
The IUPAC name of the compound shown below is
(1) 2-Bromo-6-chlorocyclohex-1-ene
(3) 3-Bromo-1-chlorocyclohexene
34.
[AIEEE 2004]
[AIEEE 2006]
(2) 6-Bromo-2-chlorocyclohexene
(4) 1-Bromo-3-chlorocyclohexene
The increasing order of stability of the following free radicals is :
•
•
•
•
•
•
[AIEEE-2006, 3/220]
(1) (C6H5)3 C < (C6H5)2 C H < (CH3)3 C < (CH3)2 C H
•
•
(2) (C6H5)2 C H < (C6H5)3 C < (CH3)3 C < (CH3)2 C H
•
•
•
•
•
•
•
(3) (CH3)2 C H < (CH3)3 C < (C6H5)3 C < (C6H5)2 C H
•
(4) (CH3)2 C H < (CH3)3 C < (C6H5)2 C H < (C6H5)3 C
35.
36.
The correct order of increasing acid strength of the compounds
[AIEEE-2006, 3/220]
(a) CH3CO2H
(b) MeOCH2CO2H
(c) CF3CO2H
(d)
(1) d < a < c < b
(2) d < a < b < c
(3) a < d < c < b
(4) b < d < a < c
The IUPAC name of
(1) 5,5-Diethyl-4, 4-dimethylpentane
(3) 1,1-Diethyl-2, 2-dimethylpentane
[AIEEE 2007, 3/120]
(2) 3-Ethyl-4, 4-dimethylheptane
(4) 4,4-Dimethyl-5, 5-diethylpentane
37.
Which one of the following is the strongest base in aqueous solution ?
(1) Trimethylamine
(2) Aniline
(3) Dimethylamine
38.
The IUPAC name of neopentane is :
(1) 2, 2-dimethylpropane
(3) 2, 2-dimethylbutane
[AIEEE 2009, 4/144]
(2) 2-methylpropane
(4) 2-methylbutane
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
[AIEEE-2007, 3/120]
(4) Methylamine
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Organic Chemistry By
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M.Sc. IT-BHU
ELECTRONIC EFFECT # 29
39.
40.
41.
Arrange the carbanions, (CH3)3 C , C Cl3, (CH3)2 C H, C6H5 C H2 in order of their decreasing stability :
[AIEEE-2009, 4/144]
(1) (CH3)2 C H > C Cl3 > C6H5 C H2 > (CH3)3 C
(2) C Cl3 > C6H5 C H2 > (CH3)2 C H > (CH3)3 C
(3) (CH3)3 C >(CH3)2 C H> C6H5 C H2 > C CCl3
(4) C6H5 C H2 > C Cl3 > (CH3)3 C
> (CH3)2 C H
The correct order of increasing basicity of the given conjugate bases (R = CH3) is : [AIEEE-2010, 4/144]
(1) RCO O  HC  C  R  N H2
(2) R  HC  C  RCO O  N H2
(3) RCO O  N H2  HC  C  R
(4) RCO O  HC  C  N H2  R
The order of stability of the following carbocations
[JEE Mains 2013,04/120]
is :
(1) III > II > I
(2) II > III > I
(3) I > II > III
(4) III > I > II
42.
A solution of ( – ) –1 – chloro – 1 – phenylethane in toluene racemises slowly in the presence of a small
amount of SbCl5, due to the formation of :
[JEE Mains 2013,04/120]
(1) carbanion
(2) carbene
(3) carbocation
(4) free radical
43.
Arrange the following compounds in order of decreasing acidity :
(1) II > IV > I > III
44.
45.
(2) I > II > III > IV
(3) III > I > II > IV
[JEE Mains 2013,04/120]
(4) IV > III > I > II
For which of the following molecule signifficant   0 ?
[JEE Mains 2014,04/120]
(a)
(b)
(c)
(d)
(1) Only (c)
(2) (c) and (d)
(3) Only (a)
(4) (a) and ( b)
Considering the basic strength for amines in aqueous solution ,which one has the smallest pKb value ?
(1) (CH3O3N
(2) C6H5 NH2 (3) (CH3)2 NH
(4) CH3 NH2 [JEE Mains 2014,04/120]
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
Organic Chemistry By
VKP Sir
M.Sc. IT-BHU
ELECTRONIC EFFECT # 30
EXERCISE # 1
1.
(C)
2.
(C)
3.
(B)
4.
(A)
5.
(D)
6.
(B)
7.
(C)
8.
(D)
9.
(B)
10.
(D)
11.
(C)
12.
(A)
13.
(C)
14.
(C)
15.
(D)
16.
(B)
17.
(A)
18.
(C)
19.
(B)
20.
(C)
21.
(A)
22.
(D)
23.
(B)
24.
(D)
25.
(B)
26.
(C)
27.
(C)
28.
(B)
29.
(B)
30.
(C)
31.
(B)
32.
(A)
33.
(A)
34.
(D)
35.
(C)
36.
(A)
37.
(B)
38.
(D)
39.
(C)
40.
(C)
41.
(C)
42.
(A)
43.
(B)
44.
(B)
45.
(B)
46.
(B)
47.
(A)
48.
(C)
49.
(B)
50.
(A)
51.
(C)
52.
(B)
53.
(A)
54.
(C)
55.
(C)
56.
(C)
EXERCISE # 2
1.
B, E, I
2.
B, D
3.
(a) is resonance form; (b) is not resonance form due to different number of I.p. and b.p.
(c) is not resonance form due to different number of I.p and b.p.
4.
a = Resonance form, b = A, c = C, d = A & B, e = B & C, f = 0, g = B, h = B
5.
(A) sp2 , (B) sp2 , (C) sp2 , (D) sp2
6.
HC  C – C  CH in it all carbon are sp hybridized C – C  bond is shorter both CH3CH3 &
CH2 = CH –CH = CH2
7.
(a) I , (b) I , (c) II , (d) II
8.
(a)
(b)
(c)
(d)
(e)
(f)
(g)

(i) CH3 – C H –CH = CH – CH = CH – CH3

(h)

(j) CH3 – C H –CH = CH – CH = CH2

(k) H2 C – CH = CH – CH = CH2
(l)
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
(m) me – CH = C l
Organic Chemistry By
VKP Sir
M.Sc. IT-BHU
ELECTRONIC EFFECT # 31

9.
(A) (Me)2 C  N H2
10.
(a) II ,
13.
(a) ii , (b) ii, (c) ii, (d) i , (e) i
14.
(a) I , (b) I , (c) I , (d) II, (e) II
15.
(a) I , (b) II, (c) II , (d) II, (e) I
16.
(a) , (c) , (d) , (g) , (l) , (m) are True
17.
(a), (b)
18.
(a) ll , (b) l, (c) l , (d) ll
19.
(a) , (b) , (c) , (f)
20.
(a) II , (b) I , (c) I , (d) l (e) l
21.
(a) II , (b) I, (c) II, (d) II, (e) II
22.
(a) ii < iv < i < iii
23.
(a) II, (b) II, (c) II, (d) II
24.
(a) I, (b) II, (c) II, (d) I
25.
(a) A, (b) A, (c) N.A., (d) A, (e) A, (f) N.A., (g) A
26.
27.
iii > ii > i
28.
(B)
(b) II , (c) II,
(d) II,
(e) II,
(b) iii < ii < i
A>B
29.
30.
(a) 4658
(b) 4638
31.
(a) i , (b) i, (c) ii
33.
(A) (I) iv > iii > ii > i
(II) i > ii > iii > iv
(B) (I) iii > ii > i
(II) i > ii > iii
34.
(a) (i) D > C > B > A
(b) 2 > 1
(ii) E > C > D > B > A
(c) 2 < 1
(d) 1 < 2
(e) 1 > 2
35.
(a) I , (b) I , (c) II , (d) I
36.
(a) Due to resonance
(c) 4632
(d) 4656
32.
(e) 5293
A
(b) In CH2=CH–OCH3, there is single bond character due to resonance
(c) Conjugate base of CH3SH ie, CH3S is more stable than conjugate base of CH3OH, ie CH3O–.
(d) In CH2=CH–NH2 lone pair of N is delocalized
37.
(i) C > b > a
(v) c > b > a
(ix) a > c > b
(ii) c > b > a
(vi) b > c > a
(x) c > b > a
(iii) b > c > a
(vii) a > b > c
(xi) a > b > c
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
(iv) c > b > a
(viii) a > b > c
(xii) c > b > a
Organic Chemistry By
VKP Sir
M.Sc. IT-BHU
ELECTRONIC EFFECT # 32
38.
(i) b > c > a
(v) a > b
(ix) a > b
(ii) b > c > a > b
(vi) a > b > c
(x) a > b > c
(iii) c > a > b
(vii) a > b > c
(xi) a > c > b
(iv) b > a
(viii) a > b > c
(xii) c > a > b
39.
d<f<b<c<a<e
On the basis of stability of free radical formed after removal of H–.
40.
(i) b > a
(v) a > b > c
(ii) a > b > d > c
(vi) a > b > c
(iii) a > b > c > d > e
(vii) b > a
41.
(i) c > b > a
(ii) a > b > c > d
(iii) a > b
42.
(A) Second ; (B) First
43.
2C2H5OH + 2Na (46 g)  2C2H5ONa + H2
(xiii) a > b > c > d
(iv) b > c > a
(viii) b > a
(iv) c > b > a
46
 2 mole Na  1 mole H2 generate
23
It means 2g H2 gas
44.
Anthracene is 14  e’s system
i.e. threre are 7 bonds
Expected (theoretical) heat of hydrogen = –28.6 × 7 = –200.2 kcal / mol
Observed (experimental) heat of hydrogen = –116.2
 R.E. = –116.2 – (–200.2) = 84 kcal/mol
EXERCISE # 3
1.
(A) Q, R, S ; (B) Q, R ; (C) P , R. (D) P , R
4.
(A) P,R ; (B) Q, S ; (C) P, R ; (D) P, R
3.
(A) P, R, T; (B) P, R (C) S ; (D) P, Q, R
EXERCISE # 4
PART - I
1.
1, 3-Butadiene shows delocalisation.
CH2 = CH – CH = CH2
– CH = CH –
So bond between second & third C-atoms show partial double bond character. Hence bond length is
shorter than C – C bond in n-butane.
2.
Carbon has higher percentage ‘s’ character in HCC¯, due to which higher electronegativity.
3.
Acidic strength Dissociation constant of acid. In given acids order of acidic strength
CH3 CHFCOOH > CH3CHBrCOOH > FCH2CH2COOH > BrCH2CH2COOH
Hence in these smallest dissociation constant for BrCH2 —CH2COOH
4.
(a) – (ii)
(b) – (iii)
(c) – (iv)
(d) – (i)
(e) – (v)
5.
6.
(A)
7.
(A)
8.
(A)
9.
(B)
10.
(A)
11.
(D)
12.
(A)
14.
(B)
15.
(D)
16.
(B)
17.
(B)
18.
(A)
19.
2
20.
(C)
21.
6
22.
(BC)
23.
(A)
PART - II
24.
(2)
25.
(3)
26.
(1)
27.
(4)
28.
(3)
29.
(3)
30.
(3)
31.
(3)
32.
(4)
33.
(3)
34.
(4)
35.
(2)
36.
(2)
37.
(3)
38.
(1)
39.
(2)
40.
(4)
41.
(4)
42.
(3)
43.
(3)
44.
(2)
45.
(3)
Physical & Inorganic By
NV Sir
B.Tech. IIT Delhi
A-479 Indra vihar, kota
Ph. - 9982433693 (NV Sir) 9462729791(VKP Sir)
Organic Chemistry By
VKP Sir
M.Sc. IT-BHU
ELECTRONIC EFFECT # 33