chemistry MCQs - 10th class Chapter 04 Mcqs

1

Compounds consisting of only carbon and hydrogen are called what?

A

Alcohols

B

Ethers

C

Hydrocarbons

D

Halides

2

Hydrocarbons are broadly divided into open chain and what other class?

A

Straight chain

B

Branched chain

C

Closed chain

D

Linear chain

3

Which of the following is an example of a saturated hydrocarbon?

A

Ethene

B

Propane

C

Ethyne

D

Benzene

4

Saturated hydrocarbons are also known as what?

A

Alkenes

B

Alkynes

C

Paraffins

D

Olefins

5

What is the general formula for alkanes?

A

CnH2n

B

CnH2n-2

C

CnHn

D

CnH2n+2

6

Unsaturated hydrocarbons containing a double bond are called what?

A

Alkanes

B

Alkenes

C

Alkynes

D

Aromatics

7

What is the general formula for alkenes?

A

CnH2n

B

CnH2n+2

C

CnH2n-2

D

CnH2n+1

8

Hydrocarbons containing a triple bond are known as what?

A

Alkanes

B

Alkenes

C

Alkynes

D

Olefins

9

What is the general formula for alkynes?

A

CnH2n

B

CnH2n+2

C

CnH2n-2

D

CnHn

10

The term 'paraffins' for alkanes means what?

A

High reactivity

B

Less affinity

C

Oil forming

D

High affinity

11

The main sources of alkanes are petroleum and what?

A

Coal gas

B

Natural gas

C

Biogas

D

Sewage gas

12

Methane constitutes about what percentage of natural gas?

A

50%

B

75%

C

85%

D

95%

13

The process of adding molecular hydrogen to alkenes and alkynes is called what?

A

Halogenation

B

Hydrogenation

C

Dehydration

D

Combustion

14

Hydrogenation of alkenes is carried out in the presence of which catalyst at 250-300 °C?

A

Zinc

B

Iron

C

Nickel

D

Copper

15

The reaction of alkanes with halogens in diffused sunlight is what type of reaction?

A

Addition

B

Elimination

C

Substitution

D

Oxidation

16

Combustion of alkanes in excess oxygen produces carbon dioxide, heat, and what else?

A

Carbon monoxide

B

Water

C

Soot

D

Hydrogen gas

17

Incomplete combustion of methane produces which toxic gas?

A

Carbon dioxide

B

Sulphur dioxide

C

Nitrogen dioxide

D

Carbon monoxide

18

What is the common name for ethene?

A

Ethylene

B

Acetylene

C

Propylene

D

Butylene

19

Alkenes are also known as 'olefins' because their first members form what with halogens?

A

Gaseous products

B

Solid products

C

Oily products

D

Acidic products

20

The preparation of ethene from ethanol using concentrated H2SO4 is an example of what?

A

Dehydration

B

Dehydrogenation

C

Hydration

D

Halogenation

21

The removal of a hydrogen and a halogen from adjacent carbon atoms is called what?

A

Dehalogenation

B

Dehydrohalogenation

C

Dehydration

D

Hydrogenation

22

The reaction of ethene with bromine water results in the product:

A

Bromoethane

B

1,2-dibromoethane

C

1,1-dibromoethane

D

Tribromoethane

23

The reaction with what substance is used to test for unsaturation in alkenes and alkynes?

A

HCl

B

H2SO4

C

NaOH

D

KMnO4 solution

24

What is ethene used for in relation to fruits?

A

Preventing spoilage

B

Artificial ripening

C

Increasing sweetness

D

As a preservative

25

Ethene is polymerized to form which common plastic?

A

Polyvinyl chloride

B

Polyester

C

Polythene

D

Neoprene

26

Which poisonous gas used in chemical warfare is made from ethene?

A

Phosgene

B

Chlorine gas

C

Mustard gas

D

Sarin

27

What is the simplest alkyne?

A

Propyne

B

Butyne

C

Ethyne

D

Pentyne

28

What is the common name for ethyne?

A

Ethylene

B

Acetylene

C

Propane

D

Methane

29

Preparation of ethyne from a vicinal dihalide involves heating with what?

A

Zinc dust

B

Alcoholic KOH

C

Conc. H2SO4

D

Water

30

The addition of two molecules of Br2 to one molecule of acetylene forms what?

A

Dibromoethene

B

Tetrabromoethane

C

Tribromoethene

D

Dibromoethane

31

The oxidation of ethyne with alkaline KMnO4 ultimately produces what acid?

A

Formic acid

B

Acetic acid

C

Glyoxal

D

Oxalic acid

32

The high-temperature flame produced by acetylene and oxygen is used for what?

A

Lighting

B

Heating homes

C

Welding

D

Sterilization

33

Which hydrocarbon is used to prepare synthetic rubber like neoprene?

A

Ethene

B

Butadiene

C

Acetylene

D

Methane

34

Low molecular mass hydrocarbons like methane are typically in what state at room temperature?

A

Solid

B

Liquid

C

Gas

D

Plasma

35

Hydrocarbons are generally insoluble in which solvent?

A

Benzene

B

Carbon tetrachloride

C

Water

D

Ether

36

The reaction of methane with excess chlorine in bright sunlight is described as what?

A

Slow

B

Controlled

C

Explosive

D

Reversible

37

The first step in the halogenation of methane with chlorine in diffused sunlight produces what?

A

Dichloromethane

B

Chloroform

C

Chloromethane

D

Carbon tetrachloride

38

What product is formed when ethyl bromide is reduced with nascent hydrogen (Zn/HCl)?

A

Methane

B

Ethene

C

Ethane

D

Ethyne

39

The first member of the alkenes series is?

A

Methane

B

Ethene

C

Ethyne

D

Propene

40

Ethene glycol is produced by the oxidation of ethene with what?

A

O2

B

H2O2

C

KMnO4

D

K2Cr2O7

41

Alkenes are more reactive than alkanes due to the presence of what?

A

Single bonds

B

Pi (π) bonds

C

Sigma (σ) bonds

D

Hydrogen bonds

42

The process of cracking petroleum produces large amounts of what?

A

Alkanes

B

Alkynes

C

Alkenes

D

Aromatics

43

The flame of alkenes is smokier than alkanes because of a higher what?

A

Hydrogen percentage

B

Carbon percentage

C

Oxygen percentage

D

Nitrogen percentage

44

Acetylene is slightly soluble in water but soluble in what kind of solvents?

A

Polar solvents

B

Ionic solvents

C

Acidic solvents

D

Organic solvents

45

The conversion of vegetable oil into margarine is an example of what industrial process?

A

Halogenation

B

Hydrogenation

C

Combustion

D

Cracking

46

Which of these is used as an industrial solvent and in dry cleaning?

A

Chloroform

B

Carbon tetrachloride

C

Methane

D

Ethene

47

Which hydrocarbon is a raw material for making PVC (polyvinyl chloride)?

A

Ethene

B

Methane

C

Acetylene

D

Butane

48

Synthetic detergents are sodium salts of what?

A

Fatty acids

B

Carboxylic acids

C

Alkyl hydrogen sulphate

D

Formic acid

49

The characteristic reaction of alkenes and alkynes is what?

A

Substitution

B

Elimination

C

Addition

D

Oxidation