Hydrocarbons - Practice Test (1)


25 Questions MCQ Test Additional Question Bank | Hydrocarbons - Practice Test (1)


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This mock test of Hydrocarbons - Practice Test (1) for Class 9 helps you for every Class 9 entrance exam. This contains 25 Multiple Choice Questions for Class 9 Hydrocarbons - Practice Test (1) (mcq) to study with solutions a complete question bank. The solved questions answers in this Hydrocarbons - Practice Test (1) quiz give you a good mix of easy questions and tough questions. Class 9 students definitely take this Hydrocarbons - Practice Test (1) exercise for a better result in the exam. You can find other Hydrocarbons - Practice Test (1) extra questions, long questions & short questions for Class 9 on EduRev as well by searching above.
QUESTION: 1

Which of these fuels not a Hydrocarbon?

Solution:

hydrogen, as hydrocarbon include both ‘C’ and ‘H’ .

QUESTION: 2

The reaction given below is used to produce polythene. This is an example of _______ reaction

Solution:

Monomer units combine to form polymers.

QUESTION: 3

The addition of HBr to 1-butene gives a mixture of products A, B and C. The mixture consists of

Solution:

A and B both involve secondary carbocation but C involve primary carbocation.

QUESTION: 4

The synthesis of 3-octyne is achieved by adding a bromoalkane into a mixture of sodium amide and an alkyne. The bromoalkane and alkyne respectively are

Solution:

BrCH2CH2CH2CH3and CH3CH2C ≡ CH

QUESTION: 5

Phenyl magnesium bromide reacts with methanol to give

Solution:

Phenyl magnesium bromide reacts with methanol to give a mixture of benzene and Mg(OMe)Br , grignard reaction.

QUESTION: 6

Saturated Hydrocarbons contain

Solution:

single bond.

QUESTION: 7

The number of position isomers of C5H8 is

Solution:

n-pentyne, 3-methyl butyne, pent-2-yne

QUESTION: 8

Which of the following will not show geometrical isomerism?

Solution:

As three groups are same.

QUESTION: 9

One mole of a symmetrical alkene on ozonolysis gives two moles of an aldehyde having a molecular mass of 44 u. The alkene is

Solution:

2-butene on ozonolysis give two molecules of acetone

QUESTION: 10

A gas decolourised by KMnO4 solution but gives no precipitate with ammoniacal cuprous chloride is

Solution:

Ethene due to unsaturation decolourise KMnO4 . But do not give precipitate with ammonical cuprous chloride.

QUESTION: 11

in cycloalkanes carbon atoms form

Solution:

a ring or closed chain.

QUESTION: 12

Thus ethyne molecule consists of

Solution:

Ethyne molecule consists of one C–C σ bond, two C–H σ bonds and two C–C π bonds.

QUESTION: 13

Arrange the following hydrogen halides in order of their decreasing reactivity with propene.

Solution:

Due to weak bonding between hydrogen and iodine, due to large size of iodine.

QUESTION: 14

n-propyl bromide on treating with alcoholic KOH produces

Solution:

Elimination reaction takes place.

QUESTION: 15

What would be the product formed when 1-Bromo-3-chlorocyclobutane reacts with two equivalents of metallic sodium in ether?

(A) 

(B)

(C)

(D)

Solution:

Inta-molecular wurtz reaction.

QUESTION: 16

Which of these is not a characteristic of aromatic Hydrocarbons?

Solution:

aromatic hydrocarbon are not open chained. They are ring structures.

QUESTION: 17

In the preparation of alkynes from vicinal dihalides, the reaction is

Solution:

Twice the elimination reaction takes place, to form alkynes from vicinal dihalides.

QUESTION: 18

Arrange the following carbanions in order of their decreasing stability.

(A) H3C – C ≡≡C–

(B) H – C ≡ C–

(C) H3C−−−CH2−−H3C−−−CH2−−

Solution:

‘sp’ hybridized, more ‘s character’ more stable ‘-’ charge.

QUESTION: 19

The angle strain in cyclobutane is

Solution:

The angle strain in cyclobutane is 9°44′

QUESTION: 20

2 methylbutane on reacting with bromine in the presence of sunlight gives mainly

Solution:

Free radical mechanism.

QUESTION: 21

The number of chain isomers of C5H12 is

Solution:

2-methylbutane, 3-methylbutane, n-pentane.

QUESTION: 22

Majority of the reactions of alkynes are the examples of

Solution:

as alkynes are electron rich species.

QUESTION: 23

Arrange the following alkyl halides in decreasing order of the rate of β−−β−− elimination reaction with alcoholic KOH

Solution:

More substituted alkene is preferred by satzeff rule.

QUESTION: 24

In the following sequence of reactions, the alkene affords the compound 'B' 

  

The compound B is

Solution:

Oxidative ozonolysis leads to formation of aldehyde.

QUESTION: 25

Alkyl halides react with dialkyl copper reagents to give

Solution:

Alkyl halides react with dialkyl copper reagents to give alkanes .Reduction reaction.

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