Chemistry Aromatic Hydrocarbons MCQs Chapter 9 Class 12

Created on February 10, 2022 By Ali Durrani

Chemistry Ch 9 Class 12 Hydrocarbons

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1 / 63

The hybridization of benzene is:

sp3

sp2

sp

None of these

2 / 63

Which type of hybridization takes place in benzene?

Sp3

Sp2

Sp

Sp2 and Sp3

3 / 63

Acetylene on reacting with ammonium silver nitrate gives.

NUMS 2014
Chemistry
Hydrocarbons
Elimination Tool:

A) Silver metal

B) Silver mirror

C) Silver acetylide

D) Silver acetate

4 / 63

The reaction of benzene with bromine gives?

Allkyl bromide

Hydrogen bromide

Bromo-phenol

Bromo cyclohexane

5 / 63

The position of the double bond in alkenes can be identified by:

PMC Sample 3
Chemistry
Hydrocarbons
Elimination Tool:

A) Bromine water

B) Ozonolysis

C) Baeyer's reagent

D) Wurtz synthesis

6 / 63

Reduction of benzene is presence of Ni gives:

NUMS 2019 Cancelled
Chemistry
Hydrocarbons
Elimination Tool:

A) Cyclohexane

B) Heterocyclic

C) Alicyclic

D) Unsaturated aliphatic

7 / 63

C6H5 Is:

Phenyl

Methyl

Ethyl

Hexyl

8 / 63

Which one of the following is not a heterocyclic compound?

PMC Sample 3
Chemistry
Hydrocarbons
Elimination Tool:

A) Thiophene

B) Anthracene

C) Furan

D) Pyrrole

9 / 63

All of the following react with KMnO4 except

NUMS 2017
Chemistry
Hydrocarbons
Elimination Tool:

A) Ethane

B) Ethyne

C) Ethylbenzene

D) Ethene

10 / 63

Which catalyst is used to oxidize benzene rings?

NUMS 2019 Reconduct
Chemistry
Hydrocarbons
Elimination Tool:

A) FeBr3

B) V2O5

C) Fe + Al2O3

D) Raney Ni

11 / 63

The four bonds of carbon in methane are directed towards the corners of a:

NUMS 2014
Chemistry
Hydrocarbons
Elimination Tool:

A) Cube

B) Pentagon

C) Hexagon

D) Tetrahedron

12 / 63

Name the main product formed as a result of the following reaction

H3C – (CH2)5 – CH3 ————> Product

n-heptane

Conditions: 480 – 550 C, 150 – 399 psi V2O5

NTS 2019
Chemistry
Hydrocarbons
Elimination Tool:

A) Benzene

B) Toluene

C) Xylene

D) Cyclohexane

13 / 63

If both double and triple bonds are present in the chain, double bond is given the ______

PMC Sample 2
Chemistry
Hydrocarbons
Elimination Tool:

A) Higher number

B) Lower Number

C) Priority

D) Second position

14 / 63

Gasoline is a mixture of?

NUMS 2018
Chemistry
Hydrocarbons
Elimination Tool:

A) C3 – C5 alkanes

B) C15 – C20 alkanes

C) C11 – C15 alkanes

D) C7 – C9 alkanes

15 / 63

The bond angles in benzene ring are:

PMC Sample 1
Chemistry
Hydrocarbons
Elimination Tool:

A) 90˚

B) 60˚

C) 120˚

D) 180˚

16 / 63

In composition of natural gas, 0.17% is constituted by:

NUMS 2018
Chemistry
Hydrocarbons
Elimination Tool:

A) Methane

B) Ethane

C) Butane

D) Nitrogen

17 / 63

Alkaline KMnO4 converts ethylene into:

NUMS 2014
Chemistry
Hydrocarbons
Elimination Tool:

A) Methanol

B) Ethane

C) Ethanol

D) Ethylene glycol

18 / 63

Which of the following method is used to prepare Ethylene glycol from ethene?

PMC Practice 1
Chemistry
Hydrocarbons
Elimination Tool:

A) Dehydration

B) Hydroxylation

C) Hydration

D) Luca's test

19 / 63

Which one of the following is the correct structure of 2,2-Dimethylbutane?

PMC Sample 1
Chemistry
Hydrocarbons
Elimination Tool:

A) CH₃(CH₃)₂CCH₂CH₃

B) CH₃(CH₃)CCHCH₃

C) CH₃(CH₃)CCH₂CH₃

D) CH₃CH₂CH₂CH₃

20 / 63

Acetylene upon heating at 300 C gives:

Benzene

Alkene

Alkane

Alcohol

21 / 63

Physical properties of Ethyne is/are:

NTS 2015 DUHS and JSMU
Chemistry
Hydrocarbons
Elimination Tool:

A) It is colourless gas with a sweet smell.

B) It is sparingly soluble in water.

C) It is less dense than air.

D) It explodes on compression to a liquid because of unstable nature.

E) All of the above

22 / 63

How many chain isomers are possible for the alkane C6H14?

NTS 2016 SMBBMC
Chemistry
Hydrocarbons
Elimination Tool:

A) six

B) five

C) four

D) nine

23 / 63

Benzene when reacted with chlorine in ultraviolet rays produces:

Hexacholorocyclohexane

P-dichlorobenzene

Benzotrichloride

Benzalchloride

24 / 63

Benzene with nitrating mixture gives?

Nitro benzene

Nitro Toluene

Nitro methane

Acrylonitrile

25 / 63

Which of the following is NOT explained by Kekule structure of benzene?

PMC Sample 2
Chemistry
Hydrocarbons
Elimination Tool:

A) Hexagonal planar structure

B) The usual saturated behaviour of benzene

C) Unsaturation

D) Presence of three double bonds

26 / 63

Organic compounds in which tetravalency of carbon atom is satisfied are called as ____ ?

PMC Practice 1
Chemistry
Hydrocarbons
Elimination Tool:

A) Saturated

B) Unsaturated

C) Alkenes

D) Alkynes

27 / 63

The unhybridized p orbitals of benzene are present in the form of _________.

PMC Practice 2
Chemistry
Hydrocarbons
Elimination Tool:

A) Between the C-C bonds of benzene

B) Above and below the carbon bonds

C) In the form of a cloud above and below the benzene ring

D) None of these options is correct

28 / 63

Which of the following gases is used for welding purpose:

NTS 2019
Chemistry
Hydrocarbons
Elimination Tool:

A) ethene

B) ethane

C) propane

D) ethyne

29 / 63

Acetylene polymerizes to make:

PMC Sample 3
Chemistry
Hydrocarbons
Elimination Tool:

A) Cyclohexane

B) Benzene

C) Hexane

D) Toluene

30 / 63

The carbon number of gasoline is:

NTS 2019
Chemistry
Hydrocarbons
Elimination Tool:

A) C5 – C6

B) C6 – C7

C) C5 – C10

D) C12 – C15

31 / 63

How many Dewar Structure of Benzene are present?

2

3

4

Infinite

32 / 63

Which of the following Is formula of Benzyl Alcohol?

C6H5CHO

C6H5CH202CC6H5

C6H5CH2OH

C5H5N

33 / 63

Which of the following compounds will form a hydrocarbon on reaction with Grignard reagent?

NUMS 2014
Chemistry
Hydrocarbons
Elimination Tool:

A) CH3CH2OH

B) CH3COOCH3

C) CH3COCH3

D) CH3CHO

34 / 63

Friedel craft’s reaction gives?

Benzene

Nitrobenzene

Toluene

Alkene

35 / 63

Activation of the benzene ring in aniline can be decreased by treating with:

NUMS 2017
Chemistry
Hydrocarbons
Elimination Tool:

A) Dil HCL

B) Ethyl alcohol

C) Acetic acid

D) Acetyl chloride

36 / 63

Fuels with higher octane number can be produced by ___________.

PMC Practice 2
Chemistry
Hydrocarbons
Elimination Tool:

A) Cracking

B) Reforming

C) Decomposition

D) Isomerisation

37 / 63

Which type of bonds are broken during cracking?

PMC Practice 1
Chemistry
Hydrocarbons
Elimination Tool:

A) C- C

B) C-H

C) Both C-C and C-H

D) C-0

38 / 63

Methane gas is also known as

PMC Sample 2
Chemistry
Hydrocarbons
Elimination Tool:

A) Marsh gas

B) Pepper gas

C) Mustard gas

D) None of the above

39 / 63

n-Heptane can be converted into benzene by catalysts:

Al203, Si02, Fe203

Si02, K20, Cr203

Al203,Si02, Cr203

None of these

40 / 63

What are the products of destructive distillation of coal?

PMC Practice 1
Chemistry
Hydrocarbons
Elimination Tool:

A) Coal tar

B) Coke

C) Coal gas

D) All of above

41 / 63

Friedel-Crafts Reaction can be used for the preparation of :

Toluene

Benzene

Phenol

pABA

42 / 63

Boiling point of benzene is:

70.3

80.1

133

79.41

43 / 63

Which of the following compounds react slower than benzene in electrophilic substitution reaction?

NUMS 2019 Reconduct
Chemistry
Hydrocarbons
Elimination Tool:

A) Nitrobenzene

B) Phenol

C) Aniline

D) Toluene

44 / 63

Hydrocarbons which burn with a smoky flame are called:

NUMS 2015
Chemistry
Hydrocarbons
Elimination Tool:

A) Aliphatic

B) Aromatic

C) Alicyclic

D) None of these

45 / 63

Which derivative of benzene shows maximum reactivity in electrophilic substitution reactions?

UHS 2019
Chemistry
Hydrocarbons
Elimination Tool:

A) Benzoic acid

B) Methyl benzene

C) Benzaldehyde

D) Nitrobenzene

46 / 63

Catalytic hydrogenation of alkenes exhibits:

NUMS 2019 Cancelled
Chemistry
Hydrocarbons
Elimination Tool:

A) Substitution reaction

B) Elimination reaction

C) Addition reaction

D) Condensation reaction

47 / 63

In which of the following cases are the benzene rings isolated?

NUMS 2015
Chemistry
Hydrocarbons
Elimination Tool:

A) Naphthalene

B) Phenanthrene

C) Anthracene

D) Triphenylmethane

48 / 63

The C-H bond distance is the longest in:

NUMS 2015
Chemistry
Hydrocarbons
Elimination Tool:

A) C2H4

B) C2H2

C) C2H6

D) C2H2Br

49 / 63

Which one of the following organic compounds have the least carbon-carbon bond length?

NUMS 2017
Chemistry
Hydrocarbons
Elimination Tool:

A) Ethene

B) Ethane

C) Ethyne

D) Methane

50 / 63

How many chain isomers of Pentane is possible?

PMC Practice 1
Chemistry
Hydrocarbons
Elimination Tool:

A) Two

B) Four

C) Three

D) Five

51 / 63

Benzene is prepared in laboratory by distillation of phenol with

H202

Zn dust

Ethyl bromide

HOCI

52 / 63

Who rejected vital force theory

PMC Sample 3
Chemistry
Hydrocarbons
Elimination Tool:

A) Wohler

B) Berzelius

C) Wallus

D) Lyll

53 / 63

PolymerizatIon of ______ produces synthetic rubber.

PMC Sample 1
Chemistry
Hydrocarbons
Elimination Tool:

A) Formaldehyde

B) Choloropropene

C) Chloroform

D) Vinyl bromide

54 / 63

Stability of benzene is due to

Alternate double bonds

Electrons' cloud

Double bonds

Delocalization of electrons

55 / 63

The structure of cyclohexane is:

PMC Sample 3
Chemistry
Hydrocarbons
Elimination Tool:

A) Trigonal

B) Pentagonal

C) Hexagonal

D) None of these options is correct

56 / 63

Which of the following statements is incorrect about benzene?

All of the carbon atoms are sp hybridized.

The carbon-carbon bond lengths are all the same.

It has delocalized electrons.

The carbon-hydrogen bond lengths are all the same.

57 / 63

The ratio of σ to π bonds in benzene is:

NUMS 2019 Reconduct
Chemistry
Hydrocarbons
Elimination Tool:

A) 4:1

B) 1:4

C) 1:3

D) 3:1

58 / 63

What happens when one mole of ethane is mixed in the dark at room temperature with six moles of chlorine?

NTS 2017
Chemistry
Hydrocarbons
Elimination Tool:

A) There is no reaction.

B) CH3CH2Cl and HCl are formed.

C) CH3CCl3 and HCl are formed.

D) CCl3CCl3 and HCl are formed.

59 / 63

What is the color of silver acetylide, AgC=CAg?

PMC Practice 2
Chemistry
Hydrocarbons
Elimination Tool:

A) Red

B) White

C) Brown

D) Pinkish

60 / 63

Alkenes undergo:

UHS 2019
Chemistry
Hydrocarbons
Elimination Tool:

A) Electrophilic Addition

B) Electrophilic substitution

C) Nucleophilic substitution

D) Nucleophilic addition

61 / 63

Name the main product formed as a result of the following reaction

H3C – (CH2)5 – CH3 ————> Product

n-heptane

Conditions: 480 – 550 C, 150 – 399 psi V2O5

NTS 2019
Chemistry
Hydrocarbons
Elimination Tool:

A) Benzene

B) Toluene

C) Xylene

D) Cyclohexane

62 / 63

Alkenes are:

PMC Sample 3
Chemistry
Hydrocarbons
Elimination Tool:

A) Electrophiles

B) Nucleophiles

C) Both Options are correct

D) None of these options is correct

63 / 63

Free radical reactions take place in the presence of ______?

PMC Practice 1
Chemistry
Hydrocarbons
Elimination Tool:

A) Heat

B) Sunlight

C) Catalyst

D) Oxygen

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