chemistry MCQs - 9th class Chapter 11 Mcqs

1

Organic chemistry is defined as the chemistry of compounds of which element?

A

Oxygen

B

Nitrogen

C

Carbon

D

Hydrogen

2

Which of the following is classified as an inorganic compound despite containing carbon?

A

Methane

B

Protein

C

Carbonates

D

Lipids

3

The self-linking property of carbon to form long chains and rings is called?

A

Hydrogenation

B

Catenation

C

Combustion

D

Polymerization

4

Compounds in which carbon atoms form only single bonds with other atoms are called?

A

Unsaturated compounds

B

Aromatic compounds

C

Saturated compounds

D

Alkynes

5

Which family of hydrocarbons is the main subject of this chapter?

A

Alkenes

B

Alkynes

C

Aromatic hydrocarbons

D

Alkanes

6

What is the general formula for alkanes?

A

CnH2n

B

CnH2n-2

C

CnHn

D

CnH2n+2

7

In the IUPAC name for an organic compound, what does the 'root' part tell us?

A

The class of the compound

B

The number of carbon atoms in the longest chain

C

The groups attached to the chain

D

The type of bonding

8

The IUPAC root name 'Pent-' corresponds to how many carbon atoms?

A

4

B

5

C

6

D

7

9

What is the distinguishing feature of alkanes that makes them distinct from other compounds?

A

Their high reactivity

B

Their vibrant colors

C

Their lack of reactivity towards usual reagents

D

Their solubility in water

10

The reaction of alkanes with chlorine in the presence of sunlight is an example of what type of reaction?

A

Addition

B

Photochemical substitution

C

Combustion

D

Cracking

11

What catalyst is used in the cracking of naphtha to produce smaller hydrocarbons?

A

Nickel

B

Zinc

C

Zeolite

D

Iron

12

The process of converting alkenes and alkynes to alkanes using hydrogen gas is called?

A

Halogenation

B

Combustion

C

Cracking

D

Hydrogenation

13

Which metal is used as a catalyst for the hydrogenation of ethene to ethane?

A

Zinc

B

Sodium

C

Nickel

D

Magnesium

14

Alkanes are also referred to as paraffins, which means what?

A

High affinity

B

Very reactive

C

Little affinity

D

Light bearing

15

The unreactivity of alkanes is explained by the ______ of their C-C and C-H bonds.

A

polarity

B

ionic nature

C

non-polarity

D

metallic nature

16

Complete combustion of any alkane produces which two substances?

A

Carbon monoxide and water

B

Carbon and hydrogen

C

Carbon dioxide and water

D

Oxygen and carbon

17

What is the IUPAC name for the compound CH3-CH(CH3)-CH2-CH3?

A

Pentane

B

2-Methylbutane

C

3-Methylbutane

D

Dimethylpropane

18

The reduction of alkyl halides (R-X) to alkanes can be achieved using hydrogen generated by?

A

Ni and H2

B

Sunlight

C

Zeolite at 500°C

D

Zn and HCl

19

When methane reacts with excess chlorine, what is the final product?

A

Chloromethane

B

Dichloromethane

C

Trichloromethane

D

Tetrachloromethane

20

Which term describes a reaction where one atom or group of atoms is replaced by another?

A

Addition

B

Substitution

C

Elimination

D

Rearrangement

21

Hydrocarbons are organic compounds containing only which two elements?

A

Carbon and Oxygen

B

Hydrogen and Nitrogen

C

Carbon and Hydrogen

D

Carbon and Halogens

22

Which of the following is a use for methane mentioned in the text?

A

Making plastics

B

Making synthetic fibres

C

Making carbon black

D

Making perfumes

23

In the IUPAC system, the part of the name that tells us about the class of organic compounds is the?

A

Prefix

B

Root

C

Suffix

D

Locator

24

Which alkane cannot be prepared by the hydrogenation of alkenes or alkynes?

A

Ethane

B

Propane

C

Butane

D

Methane

25

A structural formula shows the symbols for atoms connected by short lines which represent?

A

Electrons

B

Nuclei

C

Bonds

D

Energy levels

26

The reaction CH4 + 2O2 -> CO2 + 2H2O is an example of?

A

Halogenation

B

Cracking

C

Combustion

D

Substitution

27

Which other atom is almost always present along with the carbon atom in all organic compounds?

A

Oxygen

B

Nitrogen

C

Hydrogen

D

Halogen

28

Which metal can be used to reduce alkyl halides according to the options in the book's exercise?

A

Al

B

Mg

C

Ni

D

Co

29

If naphtha undergoes a combustion reaction, what products do you expect to form?

A

Alkanes

B

Alkenes

C

CO2 and H2O

D

Both alkanes and alkenes

30

Why does a mixture of zinc and hydrochloric acid act as a reducing agent?

A

Because zinc acts as a reducing agent

B

Because atomic hydrogen is produced

C

Because molecular hydrogen is produced

D

Because chloride ions are produced

31

Which alkane will evolve the most amount of heat when it is burnt with oxygen?

A

Ethane

B

Propane

C

Butane

D

iso-Butane

32

Indicate the most reactive hydrocarbon from the given options.

A

CH3-CH3

B

CH2=CH2

C

CH≡CH

D

CH4

33

Which hydrocarbon is responsible for explosions in coal mines?

A

Butane

B

Pentane

C

Methane

D

Ethene

34

Which product will be formed when ethyl bromide (C2H5Br) is treated with Zn/HCl?

A

CH4

B

CH3-CH3

C

CH3-CH2-CH2-CH3

D

CH3-CH2-CH3

35

Which of the following is not a process of halogenation of alkanes?

A

Cracking

B

Chlorination

C

Bromination

D

Iodination

36

How many moles of oxygen will be required to completely burn propane?

A

4 moles

B

5 moles

C

3 moles

D

6 moles

37

Cracking of hydrocarbons is done at high temperature in the presence of a?

A

Acid

B

Base

C

Sunlight

D

Catalyst

38

The process of cracking helps to balance the supply and demand of which product?

A

Plastics

B

Medicines

C

Petroleum fractions

D

Synthetic fibres

39

What is the IUPAC root for a chain of 7 carbon atoms?

A

Hex-

B

Hept-

C

Oct-

D

Non-

40

The reaction of alkanes with halogens is carried out in the presence of?

A

High pressure

B

A metal catalyst

C

Sunlight

D

Water

41

Trichloromethane is also commonly known as?

A

Carbon tet

B

Freon

C

Chloroform

D

Dichloromethane

42

The bonding electrons in C-H and C-C bonds are almost equally shared, making alkanes?

A

Polar

B

Ionic

C

Reactive

D

Non-polar

43

What is the condensed formula for methane?

A

C2H6

B

CH4

C

C3H8

D

CH3OH

44

Ethyne is reduced to ethane in the presence of Nickel catalyst at what temperature?

A

100°C

B

200°C

C

300°C

D

500°C

45

What type of formula is H-C(H)(H)-C(H)(H)-H?

A

Molecular Formula

B

Condensed Formula

C

Structural Formula

D

Empirical Formula

46

Reduction of unsaturated compounds like alkenes is used to prepare?

A

Perfumes

B

Banaspati ghee and margarine

C

Plastics

D

Medicines

47

The electronegativity value of carbon is given as?

A

2.1

B

2.5

C

3.0

D

3.5

48

The electronegativity value of hydrogen is given as?

A

2.1

B

2.5

C

2.8

D

2.0

49

A mixture of natural gas (methane) and air can do what when ignited?

A

Implode

B

Liquefy

C

Explode

D

Solidify

50

In the IUPAC name 2-Methylbutane, 'methyl-' is the?

A

Root

B

Suffix

C

Prefix

D

Solvent