ECAT Chemistry Aromatic Hydrocarbons Test Online

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Chemistry

1. The nature of – COOH group is

Meta directing

Para directing

Ortho and meta directing

Ortho directing

2. Aromaticity of benzene is due to

Delocalized Λ electronic cloud

Hexagonal structure

α-framework

None

3. Ozonolysis of benzene results ultimately in

Benzene triozonide

Glyoxal

Acetatdehyde

Glyceraldehydes

4. Heating a mixture of sodium benzoate and soda lime gives

Methane

Sodium benzoate

Calcium benzoate

Benzene

5. What would be the major product of bromination of nitrobenzene?

m-product

P-product

O and P product

O-product

6. The benzene molecule contains

One double bond

Decolourized element

Two double bonds

Three double bonds

7. All are or-tho & Para directing except

NH₂

OH

NR₃

X

8. How many isomeric di-substituted products are obtained by the introduction of second group in the ring?

Two

Three

None

Four

9. Which one of the following is not monocyclic aromatic hydrocarbon?

Benzoic acid

Benzene sulfonic acid

Biphenyl

Benzaldehyde

10. In Friedal-Craft’s alkylation besides AlCl3 the other reactants are

C6H6 + NH3

C6H6 + CH3COCl

C6H6 + CH3Cl

C6H6 + CH4

11. Alkanes containing carbons C₁₈ ownwards are

Gases

Waxy solids

Solids

Liquids

12. Catalytic oxidation of alkanes is used for the preparation of

Carbonyylic acids

Ketones

Adehydes

Fatty acids

13. Compounds of carbon and hydrogen in which the tetra valency of carbon is fully satisfied are called,

Para-magnetic

Un-saturated

Magnetic

Saturated

14. Benzene has a ________ structure

Tetragonal

Heptagonal

Pentagonal

Hexagonal

15. Which of the following is not formed by the reaction of Cl₂ on CH₄ in sunlight?

CH₃CH₂CH₃

CHCl₂

CH₂Cl₂

CH₃Cl

16. Toluene is also called

Methyl benzene

None

Hydroxyl benzene

Ethyl benzene

17. Toluene reacts with CH₃Cl in the presence of anhydrous AlCl₃ to form

1,3,2 – triethyl benzene

O – and p – xylenes

M – xylene

Diphenyl methane

18. In alkanes hybridization state would be

SP²

Variable

SP³

SP

19. In alkynes the bonds between carbon atoms are

One is sigma and two are π(pi) bonds

One is π(pi) and two are sigma bonds

All sigma bonds

All pi(π) bonds

20. An alkynes having Carbon count of 20 is

Liquid

Gas

None

Solid

21. How can we locate the position of double bond is an alkene?

Hydroxylation

Polymerization

Bromination

Ozonolysis

22. Which compound is the most reactive one?

Ethyne

Ethene

Benzene

Ethane

23. Hybridization of each carbon atom in benzene ring is

sp² hybridized

dsp²

sp hybridized

sp³

24. Which one has zero octane number?

n – Heptane

n – Hexane

Decane

Iso – octane

25. According to x-ray studies, all C – C and C – H bond lengths in benzene are:

1.297 A° and 1.09 A° respectively

None of these

1.397 A° and 1.09 A° respectively

1.01 A° and 1.297 A°

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26. Which one is not an electrophile?

AlCl₃

Zn

ZnCl₂

BF₃

27. Kolb’s method of alkanes production, is actually

Hydrogenation

Electrolysis

Catalysis

Hydrolysis

28. Incomplete oxidation of alkanes yields

CO + heat

CO₂ + heat

CO and carbon black

CO & carbon black

29. Unsaturated hydrocarbons containing a double bonds are called

Paraffin

Acetylene

Alkanes

Olefins

30. In benzene carbon – carbon bonds are

Of the order 1.5

3 single and 3 double

Double covalent

Single covalent

31. Toulene is a compound in which benzene has a substituent

+NH₂ group

-CHO group

-CH₃ group

-OH group

32. Which of the following compounds has longest C – H bond?

Ethene

Ethane

Ethyne

Benzene

33. The compound prepared by a substitution reaction of benzene is

Hexabromo cyclohexane

Glyoxal

Cyclohexane

Acetophenone

34. When benzene reacts with air in the presence of V₂O₅ as a catalyst the product is

C₂O + H₂O

Maleic acid

Maleic anhydride

CO + H₂O

35. What would be the product when Cl₂ is passed through benzene in sunlight?

Reaction is not possible

Dichlorodemzene

Hexachlorobenzene

Monochlorbenzene

36. Benzene reacts with ozone and gives

Maleic anhydride

Benzoic acid

Glyoxal

Glycerin

37. Sulphuric acid generates nitronium ion by reacting with

Nitric acid

Nitrous acid

Nitrogen gas

Potassium nitrate

38. Alkanes are soluble in all except

Benzene

Water

Carbon tetra chloride

Ether

39. Identify the compound which has a bond angle of 109.5°

Ethere

Methane

Ethyne

Benzene

40. The nature of –Cl group is

Ortho directing

Ortho and para directing

Para directing

Meta directing

41. Benzene is obtained by fractional distillation of

Anthracene oil

Light oil

Heavy oil

Middle oil

42. The benzene molecule contain

Three double bonds

One double bond

Two double bonds

Delocalized Λ electron charge

43. When alkyl is treated with chlorine in the presence of sunlight?

1,3,5 trichloro product is formed

1,4 dichloro product is formed

1,3 dichloro product is formed

Only alkyl group is substituted

44. All the carbons of benzene are

SP³ hybridized

Not hybridized at all

Variably hybridized

SP² hybridized

45. The next homologue of C₁₀H₂₂ will be

C₉H₂₀

C₁₂H₂₆

C₁₃H₂₈

C₁₁H₂₄

46. The process in which orbitals of different energies and shapes mix up with each other to give equivalent orbitals is called,

Polymerization

Hybridization

Carbonization

Isomerisation

47. Which property of benzene may be directly attributed to the stability associated with it delocalized structure?

It enthalpy change of formation is positive

It tends to undergo substitution rather than addition reaction

It does not conduct electricity

It has a low b.p

48. Cracking is a process by which higher hydrocarbon are broken down into low boiling hydrocarbon. Which one is not generally a procedure for cracking:

Thermal cracking

Normal cracking

Stem cracking

Catalytic cracking

49. An alkane is produced when an alkyle halide reacts with zinc in the presence of

CH₃COOH

None

HCl

Both a & b

50. Amongst the following, the compound can be most readily sulphonated is

Chlorobenzene

Benzene

Toluene

Nitrobenzene

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51. The order of reactivity of halogen acids with alkenes is

HF > HBr > HCI > HI

HCI > HBr > HI

None of these

Hl > HBr > HCI

52. Which of the following possesses the highest melting point?

m-Dichlorobenzene

p-Dichlorobenzene

o-Dichlorobenzene

Chlorobenzene

53. The structure of benzene is

Pyramidal

Tetrahedral

Square planer

Hexagonal

54. Which of the following is not an organic compound

Methane

Ammonium cyanate

Glucose

Urea

55. Which of the following is not an electrophilic substitution reaction of benzene?

Nitration

Fridel – Craft alkylation

Free radical chlorination of benzene

Sulphonation

56. The IUPAC name of the compound having the formula (CH3) 3 C – CH – CH2 is

1,1,1-Trimethyl-3-propene

3,3,-Dimethyl-1-butene

3,3,3-Trimethyl-1-propene

1, 1-Dimethyl-3-butene

57. Length of carbon – carbon bond is least in

Ethanol

Ethane

Ethanol

58. The rotation of two carbon atoms joined by double bond would happened only if

Both bonds are broken

None of these

Sigma bond is broken

Pi bond is broken

59. Which one can give white PPt. with silver nitrate (aminooxical)?

2-Pentyne

1-Pentene

Pentane

1-Pentyne

60. Λ – electronic cloud of alkenes can easily be attacked by

Cannot be predicted

Electrophiles

Non-metals

Nuclophiles

61. Which of the following gases is used for illuminating purpose?

Butane

Ethane

Propane

Methane

62. Sp³ hybridization occurs when carbon is bound to

Two other atoms

Four other atoms

One other atoms

Three other atoms

63. Alkynes are colourless & odourless except

Acetylene

Butyne

Propyne

Pentyne

64. The method involved for electrolysis of Na or K salts of carboxylic acids

Clemmensen

Sabatier’s sendrens reaction

Kolbe’s method

Wolf kishner reduction

65. The general formula for alkenes is

D

B

C

A

66. The addition of unsymmetrical reagent to an unsymmetrical alkene is in accordance with the rule

Markownifov’s rule

Hund’s rule

Paili’s exclusion principle

Auf bau principle

67. Benzene + Ozone → Y, in this sequence Y is

Benzene diozonide

Succinic acid

Benzene triozonide

Benzene monoozonide

68. Which method is not used for the preparation of alkanes?

Dehyedro halogenation of alkyl halides

Dehydration of alcohol

Partial hydrogenation of alkanes

Dehalogenation of vic – dilahalides

69. Which compound is the most reactive one?

Benzene

Ethyne

Ethene

Ethane

70. Formula of chloroform is

CH₂Cl₂

CH₃Cl

CCl₄

CHCl₃

71. When a compound X is passed through a dilute alkaline solution of KMnO₄ the pink colour of solution is discharged. The compound X is possibly

Benzene

Ethene

Ethane

Methane

72. The electrophile in aromatic sulphonation is

SO₁

H₂SO₄

HSO₄

SO₃⁺

73. Alkyl benzenes are readily oxidized by acidified

KMnO₄

H₂SO₄

K₂CO₃

MnO₄

74. What type of hybridization is present in each carbon of following compound? HC ≡ C – C ≡ CH is

SP²

SP

Two SP² and two SP

Two SP³ and two SP

75. CnH₂n is the general formula of

Alkanes

Alkenes

None of these

Alkynes

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76. Benzene mostly undergo

Elimination reactions

All

Substitution reaction

Addition reaction

77. Molecular formula of benzene resembles with

None of these

Alkyne

Alkene

Alkane

78. Which is the C – C bond length in benzene among the following?

134 A°

1.54 A°

120 A°

139 A°

79. Which compound was recognized the parent member of aromatic compounds?

Toluene

Benzene

Phenol

Aniline

80. During the preparation of alkynes the active metals that react with tetra halo-alkanes are

Both a and b

None

Mg

Zn

81. Which of the following species participate in sulphonation of benzene ring?

SO¯₂

HSO¯₃

SO₃

H₂SO₄

82. When benzene react with acetyl chloride, what would be the product?

Acetophenone

Chlorobenzene

Alkyl benzene

Toluene

83. A molecular orbital is formed by the linear combination of two atomic orbitals. A molecular orbital must accommodate __________ electrons

5

4

3

2

84. The difference between amount of heat actually released and that of calculated is called

Bonding energy

Activation energy

Transition energy

Resonance energy

85. The nitration of benzene takes place when it is heated with a mixture of conc. HNO₃ and conc. H₂SO₄ at 50°C in ratio of

1 : 1

1 : 2

2 : 1

1 : 3

86. Benzene is not prepared from

Bromo benzene

Benzoic acid

Phenol

Acetylene

87. The main halogenations agent is

X

X²

X¯

X⁺

88. Physical properties of alkanes increases with increase of all physical constants except

Melting points

Boiling points

Solubility

Density

89. An organic compound, on treatment with Br2 in CCl4 gives bromoderivative of an alkene. The compound will be

CH ≡ CH

CH3 – CH = CH2

H2C = CH2

CH3CH = CHCH3

90. Which of the following is complex?

CaSO₄. 0.5H₂O

C₆H₁₂O₆

(C₆H₁₀O₅)n

CH₄

91. A gas decolourizes KMnO₄ (soln) but does not give precipitates with ammonical solution of AgNO₃. It is

CH₂ = CH₂

CH ≡ CH

CH₄

C₂H₆

92. Which one of the following can be used as catalyst in Friedal Craft’s reaction?

AlCl₃

HNO₃

ZnCl₂

HCl

93. When will cyclic compounds show aromaticity according to Huckel rule? The correct statement is when it has

(4 π + 2) o electrons

(4n – 2) π electrons

4 π electrons

(4 + 2) π electrons

94. The addition of HBr is easiest with

CH3 – CH = CH2

CH2 = CHCl

ClCH = CHCl

(CH3)2 C = CH2

95. Which is not the characteristic property of organic compounds?

They exist in homologous series

They form long chain compounds

Organic compounds are water soluble

Organic compound chain compounds

96. Benzene is prepared from n-hexane in the presence of catalyst

Al₂O₃

Cr₂O₃

SiO₂

All above

97. Kolb’s method is not useful for the production of

Propane

Ethane

Methane

Butane

98. Write the name of following alkene CH₂ = CH – CH = CH₂

1,3 butadiene

Buta – 1, 3-diene

Both a and b

None

99. An alkene forms isomers if the number of carbon atoms is at least

3

2

4

1

100. Which species represents the electrophile in aromatic nitration?

NO⁺₂

NO¯₂

NO₂

NO¯₃

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101. The reaction in which ketone is reduced to the alkane is called

Cannizzaro

None

Kolb

Clemmensen

102. Which one does not decolourized KMnO₄?

All above

Alkynes

Alkenes

Benzene

103. Which of the following contains single bonds?

Benzene

Alkene

Alkane

Alkyne

104. Benzene has a structure

Planar hexagonal

Hexagonal

Tri-angular

Pyramidal

105. Nitration of toluene takes place at

o-position

p-position

m-position

Both ‘o’ and ‘p’ positions

106. The unreactivity of alkanes is based upon

Both A and B

Non-polarity of the bonds

None of these

Inertness of sigma-bond

107. The method used only for the production of symmetrical alkanes

Clemmenen

Cannizzaro

Kolb’s method

Wolf kishner

108. The alkynides are used for the _______ of alkynes

Seperation

All of these

Purification

Pxperation

109. Furan is a five membered ring in which one position is occupied by

-O-

None

H-O-

H-N-

110. Amongst the following the strongest O and P-directing group is

Cl

-Br

C₆H₅-

OH

111. Choose the strongest o’,p’ directing group among the following

-OH

-Cl

-Br

-C₆H₅

112. Benzene can be obtained by heating either benzoic acid with X or phenol with Y.X and Y are respectively

Zinc dust and soda lime

Zinc dust and sodium hydroxide

Soda lime and copper

Soda lime and zinc dust

113. The term aromatic was derives from

Latin

Greek word

English

Russian

114. Which one can react with metal to liberate H₂ – gas?

C₂H₂

CH₂ ≡ CH₂

CH₄

C₃H₈

115. Which one is the catalyst in Friedle Craft’s alkylation?

Al₂O₃

ZnCl₂

Zn

AlCl₃

116. Write the name of following compound

2 – methyle hexene

4 – ethyle – 2 – methyle hexene

5 – methyle – 2 – hexane

3 – ethyle – 3 – methyle hexene

117. During nitration of benzene, the active nitrating agent is

NO₂¯

HNO₃

NO₂⁺

NO₃¯¹

118. The process in which one s and two p orbitals mix up with each other is called

SP³-hybridization

Sp²-hybridization

Dsp²-hybridization

Sp-hybridization

119. Which reaction sequence would be best to prepare 3-chloro-aniline from benzene?

Chlorination, nitration, reduction

Nitration, reduction, acylation, chlorination, hydrolysis

Nitration, reduction, chlorination

Nitration, chlorination, reduction

120. Octane number can be changed by

Isomerisation

Alkylation

Cyclisation

All of these

121. How many molecules of chlorine adds in benzene in the presence of sunlight

One

Two

Three

Four

122. The octane number is 100 for

n-hexane

Neo-Pentane

Isooctane

Neo-octane

123. In a resonance structure of a molecule

Arrangement of atoms should be same

Pairing schame of e¯ should be same

All are true

Same energy

124. Which one of the following belongs to meta directing group?

Keto group

Alkyl group

Halogens

Phenyl group

125. Alkanes cannot show cis-trans isomerism

0¯ bond is stronger then Λ-bond

The bond angle is 109.5°

Alkanes possess three groups attached to each carbon

0¯ bond required less energy to be rotated

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126. Aromatic hydrocarbons are the derivatives of

Cyclohexane

Normal series of parafins

Benzene

Alkene

127. The method in which alkanes prepared by alkyle halides in the presence of palladium – charcoal, is

Electrolysis

Hydrogenolysis

Hydrogenation

Hydrolysis

128. The empirical formula of benzene is determined by

IR spectra

U.V

Elemental analysis

NMR spectra

129. The presence of a double bond is a compound is the sign of

Substitution

None of these

Unsaturation

Saturation

130. Most common reactions of benzene and its derivatives are

Electrophilic substitution reactions

Nucleophilic substitution reactions

Electrophilic addition reactions

Nucleophilic addition reactions

131. Benzene is obtained from benzene sulphonic acid by treating with

HCl

NaHCO₃

H₂O

NaOH

132. During nitration of benzene the active nitrating agent is

NO⁺₂

NO₂

NO¯₂

NO¯₃

133. A six membered ring containing one double bond called

None of these

Cyclohexadiene

Cyclohexene

Cyclohexane

134. The components of petroleum can be separated due to

Having different chemical properties

Having different M.P.

Having different B.P.

Having different physical states

135. The hydrocarbon used for polymerization is

Alkenes

Alkynes

All of these

Alkanes

136. When benzene is burnt in free supply of air, it is completely oxidized to

CO

CO₂.H₂O

None

H₂CO₃

137. Alkynes can be prepared by electrolysis in Kolb’s electrolytic method of

Ono carboxylic acid

Salt of unsaturated di-carboxylic acid

Salt of unsaturated mono carboxylic acid

Dicarboxylic acid

138. Which of the following compounds contains a triple bond?

Benzene

Alkene

Alkane

Alkyne

139. Meta directing group decreased the …………. Of benzene ring.

None

Physical activity

Chemical reactivity

Density

140. In which one of the following compound rings are not fused together at ortho positions

Phenanthrene

Naphthalene

Diphenyemethane

Anthracene

141. In sp² type hybridization the three equivalent sp² orbitals lie in the same plane and at angle of

0°

120°

180°

60°

142. The four bonds of carbon in methane are directed towards the corners of

Tetrahedron

Hexagon

Cube

Pentagon

143. The functional group isomer of dimethyl –ether is

Propyl alcohol

Butyl alcohol

Ethyl alcohol

Diethyl ether

144. The total number of σ-bonds in benzene are

12

9

15

6

145. All C – C bond lengths in benzene are

1.54 A°

1.20 A°

1.397 A°

1.09 A°

146. Aromatic compounds burn with a sooty flame because

They have a cyclic structure

They are resistant to react with O₂

They have high percentage of C

They have high percentage of H₂

147. Aromatic hydrocarbons are the derivatives of

Normal series of paraffin

Benzene

Alkenes

Cyclohexane

148. Who discovered benzene?

Berzellius

Kekule

Faraday

Schwan

149. Which of the following acid can be used as a catalyst in Friedel Craft’s reactions?

BeCl₂

NaCl

HNO₃

AlCl₃

150. Benzene was discovered by Michael Faraday’s in

1824

1827

1826

1825

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151. Benzene cannot undergo

Substitution

Addition

Oxidation

Elimination

152. Substituted phenyl groups are called

Alkyle groups

Aryl groups

Acyl groups

Phenyl groups

153. Benzene cannot under go

Substitution reactions

Addition reactions

Oxidation reactions

Elimination reactions

154. Which reaction is too vigorous to control?

Iodination

Fluorination

Chlorination

Bromination

155. The order of reactivity of halogen acids towards alkenes

HBr > HCl > HI

HCl > HBr

HCl > HBr > Hl

Hl > HBr > HCl

156. Ether shows the phenomenon of

Metamerism

Cis – trass isomerism

Position isomerism

Chain isomerism

157. The treatment of benzene with isobutene in the presence of sulphuric acid give

No reaction

Tert-Butyl benzene

Isobutyl benzene

n-Butyl benzene

158. Hydrocarbons contain

C and H only

C, H, and O only

C, H, O and N only

C and S only

159. Polymerization if ethane take place at pressure of 100 atm and a temperature of

400°C

600°C

800°C

200°C

160. All C – H bond lengths of benzene ring is

1.08 A⁰

1.07 A⁰

1.10 A⁰

1.09 A⁰

161. The stability of aromatic compounds decreases with -------- in the no. of its resonance structure

Decrease

Increase

Remain constant

Partially decreases

162. Which one of the following is (m – xylene)?

1,5 dimethyl benzene

1,3 dimethyl benzene

1,2 dimethyl benzene

1,4 dimethyl benzene

163. Raney – nickel is the alloy of Ni with

Pt

Al

Pd

Cu

164. The three alternate single and double bonds in the benzene ring are called

None of these

Resonating bonds

Both A and B

Conjugate bonds

165. Identify the compounds formed when ethane combines with water in the presence of 10% sulphuric acid and HgSO₄ as catalyst

Glycol

Carbinol

Methanol

Ethanol

166. The electron releasing effect of methyl group is significant and it makes ring a good

Hydrophobic

Electrophilic

Nucleophobic

Nucleophilic

167. Which one of the following is a heterocyclic compound?

Cyclohexanol

Anthracene

Pysidence

Phenol

168. With AlCl₃ as catalyst, benzene reacts with alkyl and acyl chlorides giving alkylated and acyclated benzene respectively. This reaction is known as

Halogenation reaction

Friedel and Crafts reactions

Nitration reaction

Aldol condensation

169. Kolb’s method has limited synthetic applications due to

Expensive catalysis

Number of side products produced

Salts used are very expensive

Slow reaction

170. The characteristic reactions of alkanes are

Condensation reactions

Polymerization reactions

Substitution reactions

Addition reactions

171. The electrophile in aromatic sulphanation is

H₂SO₄

HSO¯₄

SO₃

SO⁺₃

172. Isomerism which is only found is alkanes?

Metamerism

Position isomerism

cis – trans isomerism

Functional group isomerism

173. Which is true about benzene

Due to delocalized Λ electronic cloud it does not give addition reactions easily

Due to double bonds it easily give addition reaction

All C – C bonds are different in benzene

Di-substitution of benzene give six isomers

174. The major reaction occurring in the engines of automobiles is

Oxidation

Combustion

Reduction

Decomposition

175. Which class of compound is more reactive?

Alkyne

Alkane

None

Alkene

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176. Point out the polycyclic compound among the following

Xylene

Naphthalence

Cumence

Styrene

177. The C-C bond angles in benzene ring are

121⁰

122⁰

119⁰

120⁰

178. Which is a mixture of low boiling hydrocarbon?

Natural gas

Petroleum

Graphite

Wood

179. The hydrocarbon which is used as an illuminating agent

Methyne

Methane

B & C

Methene

180. Benzene undergoes catalytic (V₂O₅) oxidation at 500°C to give

Maleic acid

Maleic anhydride

Acetylene

Benzoic acid

Total Questions:	180
Time Allowed:	60 Minutes
Total Marks:	180
How to Attempt Test:	Please choose the right Option in MCQ-type question.
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