General Organic Chemistry - Test

Questions

1. Aniline, o-nitroaniline, m- nitroaniline, p- nitroaniline

Correct basicity order of the given amines is:

(a) Aniline> m-nitroaniline> p- nitroaniline> o-nitroaniline

(b) O-nitroaniline > Aniline> m-nitroaniline > p- nitroaniline
(c) m-nitroaniline > p- nitroaniline > o-nitroaniline > Aniline
(d) m-nitroaniline > Aniline> o- nitroaniline > p- nitroaniline

2. What is the degree of unsaturation of the following compound?

(a) 13
(b) 16
(c) 14
(d) 10

3. Cyclooctatetraene is ?
(a) Aromatic
(b) Non aromatic
(c) Anti aromatic
(d) Partially aromatic

4. Number of Alpha hydrogens in the 1-methyl cyclohexene is?

(a) 4
(b) 5
(c) 7
(d) 6
5. Geometry of methyl free radical is?
(a) Pyramidal
(b) Planar
(c) Tetragonal
(d) Linear

6. The number of sigma and pi-bonds in 1-butene-3-yne are

(a) 5σ and 5π

(b) 7σ and 3π

(c) 8σ and 2π

(d) 6σ and 4π

7. The IUPAC name of

is
(a) 1, 1-diethyl-2, 2-dimethylpentane
(b) 4, 4-dimethyl-4, 4-diethylpentane
(c) 5, 5-diethyl-4, 4-dimethylpentane
(d) 3-ethyl-4, 4-dimethylheptane

8. Inductive effect of –CH3 group operates in

(a)

(b)

(c)

(d) All of these

9. In the given anion, –ve charge is delocalized on

(a) One atom

(b) Three atom
(c) Four atom
(d) Five atom

10. Which of the following represents the correct order of stability of the given
carbocations?

(a) III > I > II

(b) I > III > II
(c) III > II > I
(d) II > III > I

11. IUPAC name of the following compound is:

(a) 1-methylbicyclo [4,3,0] nonane

(b) 8-methylbicyclo [4,3,0] nonane
(c) 3-methylbicyclo [4, 3, 0] nonane
(d) 4-methylbicyclo [4, 3, 0] nonane

12.

In the nomenclature of , priority order is:

(a) – CH3 <– OH < C = C (first)
(b) – OH <– CH3 < C = C (first)
(c) – OH < C = C <– CH3 (first)
(d) –CH3 < C = C <– OH (first)
13. Consider the following compounds

Hyper conjugation occurs in:

(a) II only
(b) III only
(c) I and III
(d) I only

14.

(a) –NO2 in compound I is poor inductive group

(b) –NO2 in compound I is stronger inductive group
(c) –NO2 in compound I is stronger –M group
(d) –NO2 in compound I is weaker –M group

15. Observe the following pairs of organic compounds:

(i) C4H9OH and C5H11OH
(ii) C7H15OH and C5H11OH
(iii) C6H13OH and C3H7OH
Which of these pair is a homologous series according to increasing order of carbon
atom.
(a) iii only
(b) ii only
(c) i only
(d) All of these
16. What is the IUPAC name of the compound shown?

(a) γ -amino-α -hydroxybutyric acid

(b) 4-amino-2-hydroxybutanoic acid
(c) α -amino-γ -hydroxybutyric acid
(d) 1-amino-3-hydroxybutanoic acid

17. Which of the following forms of ethane is more stable?

(a) Staggered conformation
(b) Eclipsed conformation
(c) Both are equally stable
(d) None of the above

18. The minimum number of carbon atoms in alkane molecule to show chain
isomerism is
(a) 2
(b) 3
(c) 4
(d) 5

19.

Which of the above given compounds can exhibit Tautomerism?

(a) I and III
(b) II and III
(c) I, II and III
(d) I and II
20. The compounds

are
(a) Chain isomers
(b) Metamers
(c) Position isomers
(d) Both (a) & (b)

21. Which of the following conformers for ethylene glycol is most stable ?

(a)

(b)

(c)

(d)

22. In the following the most stable conformation of n-butane is :

(a)

(b)

(c)

(d)
23. The number of geometrical isomer for CH3 – CH = CH – CH = CH – CH = CH2
(a) 2
(b) 4
(c) 6
(d) 8

24. The number of cis-trans isomer possible for the following compound

(a) 2
(b) 4
(c) 6
(d) 8

25. Acids and esters having the same number of carbon atoms are:
(a) Functional isomers
(b) Tautomers
(c) Metamers
(d) Not isomers

26. Give its IUPAC name.

(a) 3, 3-Dimethyl propane

(b) 2, 2-Dimethyl propane
(c) n-butane
(d) Isopropyl butane

27. Inductive effect of which atom or group is taken as zero to compare inductive effect
of other atoms ?
(a) Hydrogen
(b) Chlorine
(c) Carbon
(d) Oxygen
28. Which one is the butyl group?
(a) -C2H5
(b) -C4H9
(c) -CH3
(d) -C3H7

29. Which carbocation is the most stable?

(a)

(b)

(c)

(d)

30. Which of the following will not show cis-trans isomerism?

(a) CH3—CH=CH—CH3
(b) CH3—CH2—CH=CH—CH2—CH3

(c)

(d)
31. The order of stability of the following carbocations

I) CH2 = CH − C H2
⊕

II) CH3 − CH2 − C H2

⊕

III) CH3 − C H − CH3

(a) III > II > I

(b) II > III > I

(c) I > III > II

(d) III > I > II

32. Butanone is a four carbon compound with the functional group ______.
(a) Carboxylic acid
(b) Aldehyde
(c) Ketone
(d) Alcohol

33. The structures below are:

(a) conformational isomers

(b) Structural isomers
(c) Geometrical isomers
(d) None of the above

34. Inductive effect involves

(a) displacement of σ -electrons resulting in polarisation
(b) displacement of π -electrons resulting in polarisation
(c) delocalisation of σ -electrons
(d) displacement of π -electrons
35. Give its IUPAC name.

(a) 3, 3-Dimethyhexane
(b) 2, 2-Dimethylhexane
(c) 2-ethyl-2-methylpentane
(d) 2-methyl-2-propylhexane

36. Why is benzoic acid less acidic than 2 -methyl benzoic acid?
(a) +H effect of CH3 group.
(b) Ortho effect
(c) SIP effect
(d) None of these

37. Which one of the following compounds is not aromatic?

(a)

(b)

(c)

(d)

38. How many primary, secondary, tertiary and quaternary carbon atoms are present
in the following compound?

(a) One primary, two secondary and one tertiary

(b) Five primary, three secondary
(c) Five primary, one secondary, one tertiary and one quaternary
(d) Four primary, two secondary and two quaternary
39. Number of possible structural isomers (Only alcohol) of the compound with
molecular formula C5H12O
(a) 8
(b) 9
(c) 7
(d) 6

40. Which of the following will have the least hindered rotation around carbon-carbon
bond?
(a) ethane
(b) ethylene
(c) acetylene
(d) hexachloroethane

41. How many structural isomers of molecular formula C3H6BrCl?

(a) 4
(b) 5
(c) 6
(d) 7

42. What is the IUPAC name of the following compound:

(a) 2-hydroxy-3-methyl butane

(b) 3-methyl butanol
(c) 3-methyl-2-butanol
(d) 2-methyl-3-hydroxybutane

43. What is the IUPAC name of the below compound?

(a) Butyne
(b) Propyne
(c) Hexyne
(d) Pentyne
44. The IUPAC name of neopentane is
(a) 2-methylbutane
(b) 2,2-dimethylpropane
(c) 2-methylpropane
(d) 2,2-dimethylbutane

45. Write the name of an alcohol with three carbon atoms in its molecule.
(a) Butanal
(b) Propanol
(c) Propanal
(d) Butanol

46. Benzene has a molecular formula of _______.

(a) C 5 H12

(b) C 6 H8

(c) C 6 H6

(d) C 7 H7

47. Number of π -electron in (C4H4)2– is

(a) 2
(b) 4
(c) 6
(d) 8

48. Hyperconjugation usually involves the delocalisation of

(a) σ bond
(b) π bond
(c) Both σ and π bond
(d) None of the mentioned

49. Calculate the angle strain for cyclopropane

(a) 24.75o
(b) 60o
(c) 48o
(d) 109.5o
50. Molecule in which the distance between the two adjacent carbon atoms is largest
is:
(a) Ethene
(b) ethyne
(c) ethane
(d) benzene
 Answer Key

1. A 2. A 3. B 4. C 5. B 6. B
7. D 8. D 9. C 10. A 11. B 12. D
13. B 14. D 15. C 16. B 17. A 18. C
19. C 20. D 21. A 22. B 23. B 24. A
25. A 26. B 27. A 28. B 29. B 30. C
31. C 32. C 33. B 34. A 35. A 36. B
37. C 38. C 39. A 40. A 41. B 42. C
43. C 44. B 45. B 46. C 47. C 48. A
49. A 50. C
 Solutions

1. (A)
Ortho substituted anilines are usually weaker bases than aniline irrespective of the
nature of the substituent. This is called ortho effect and is due to a combination of steric
and electronic factors

2. (A)
Degree of unsaturation of a compound is calculated by the sum of numbers of rings
and pi bonds in the compound. In the given compound four rings and 9 double bonds
are present.

3. (B)
Cyclooctatetraene assumes a tub (i.e., boat-like) conformation. As it is not planar, even
though it has 4n π-electrons, these electrons are not delocalized and conjugated. The
molecule is therefore nonaromatic.

4. (C)
It contains 7 alpha hydrogens.

5. (B)
No. of hybrid orbital = No. of σ bonds + No. of lone pair = 3 + 0 = 3, So hybridisation is sp2
and geometry is planar.

6. (B)
7. (D)

3-ethyl-4, 4-dimethylheptane

8. (D)
Stability of carbocations will be decided on the basis of +I effect of –CH3 group because
inductive effect depends upon distance.

9. (C)

10. (A)
IIIrd is aromatic (most stable) and IInd is antiaromatic (least stable)

11. (B)

8-methylbicyclo [4,3,0] nonane

12. (D)

Functional group -OH, gets priority over >C=C< group. -CH3 is a substituents will gets
lowest priority in this case.
13. (B)
Only structure (III) has α-H in conjugation with free radical.
So, hyper conjugation is possible in III only.

14. (D)
Due to SIR effect in compound I, -NO2 group goes out of the plane hence it shows only -I
effect.

15. (C)
i only

Homologous series is a series of compounds with similar chemical properties and some
functional group differing from the successive member by -CH2-.

The successive members vary from each other by a -CH2- unit. And there Degree of
unsaturation is same.

16. (B)

4-amino-2-hydroxybutanoic acid

17. (A)
The staggered conformation is the most stable of all possible conformations of ethane,
since the angles between C-H bonds on the front and rear carbons are maximized
which minimizes the energy.

18. (C)
Butane can form n-butane and isobutane.
19. (C)
All of these compounds show tautomerism

20. (D)
Both have different carbon chain length.

21. (A)

Due to H-bonding stability of two gauche -OH groups its energy is decrease and it
become more stable.
22. (B)

The most stable conformation of butane is the one in which the two terminal methyl
groups are the farthest removed from each other, i.e. the anti conformation.

23. (B)
No. of Geometrical isomers = 2n

Molecule have two double bonds that showing geometrical isomerism.

So total G.I.= 4

24. (A)
Multiple Bond present in the middle of the compound can show Cis -Trans isomerism.

25. (A)
Carboxylic Acid(propanoic acid C2H5COOH) and ester(methyl acetate CH3COOCH3)

26. (B)

2, 2-Dimethyl propane

27. (A)
Hydrogen does not exert inductive effect. Its inductive effect is taken as zero. Electron-
releasing or electron-withdrawing capability of other atoms is compared with
hydrogen.

28. (B)
-C4H9 having 4 carbon and 9 hydrogen atoms is the butyl group.
29. (B)

More + R effect shown in option (b) stabilize carbocation.

30. (C)

Thus there are two requirements for cis-trans isomerism:

Rotation must be restricted in the molecule.

There must be two nonidentical groups on each doubly bonded carbon atom.

only compound in option 3 does not follows both the above conditions.

31. (C)
Structure I: Allylic carbocation
Structure II: 1o carbocation

Structure III: 2o carbocation

Allylic carbocation is the most stable among the given structures due to resonance. 2
∘
carbocations are more stable than 1∘ carbocations due to more number of alkyl
groups which have +I effect in 2∘ carbocations than in 1∘ carbocations.

So, the order of stability: I > III > II

32. (C)

Butanone contains ketone as functional group.

33. (B)
These two compounds are chain isomers.

34. (A)
Due to displacement of σ -electrons towards more electronegative atom, the bond
becomes polar. The polar bond induces polarity to the adjacent bonds, this is the
inductive effect.
35. (A)

3, 3-Dimethylhexane

36. (B)
Due to the ortho effect, ortho substituted benzoic acid is more acidic than benzoic acid.

37. (C)
Due to the presence of sp3 carbon it is not aromatic.

38. (C)

1° → primary – 5
2° → secondary – 1
3° → Tertiary – 1
4° → Quaternary – 1

39. (A)
Total number of structural isomer = 8
40. (A)
In case of ethane and hexachloroethane, there is a less hindered rotation because of
the presence of C—C single bond. Out of these, ethane has least hindered rotation
because the chlorine atom is bigger than the hydrogen atom.

41. (B)

42. (C)
Parent chain is numbered from the end nearer to OH group. Hence, the IUPAC name of
given compound is 3-methyl-2-butanol.

43. (C)

The IUPAC name is Hexyne

44. (B)

The IUPAC name of neopentane is 2,2-dimethylpropane.

45. (B)
3 carbon atoms = ‘propane’ prefix
Alcohol = ‘ol’ suffix

Hence, Propanol is the correct answer.

46. (C)
Benzene has a molecular formula of C 6 H6 .

47. (C)

48. (A)
Hyperconjugation involves the delocalisation of σ bond orbital. It is the stabilising
interaction that results from the interaction of the electrons in a σ-bond (usually C-H or
C-C) with an adjacent empty or partially filled p-orbital or a π*-orbital to give an
extended molecular orbital that increases the stability of the system.

49. (A)

∘ ∘

Angle strain =
109.5 −60 ∘
= 24.75
2

50. (C)
bond length order of C-C in
Ethane is 154pm, ethene is 134pm, ethyne is 120pm and benzene is 139pm