chemistry MCQs - 10th class Chapter 06 Mcqs

1

What percentage of the atmospheric mass lies within the lowest 11 kilometres?

A

50%

B

75%

C

90%

D

99%

2

Which gas has the highest percentage by volume in dry air?

A

Oxygen

B

Argon

C

Nitrogen

D

Carbon dioxide

3

What is the percentage of Oxygen in the atmosphere by volume?

A

78.09%

B

20.94%

C

0.93%

D

0.03%

4

The atmosphere is divided into how many regions based on temperature variation?

A

Two

B

Three

C

Four

D

Five

5

Which layer of the atmosphere is closest to the Earth's surface?

A

Stratosphere

B

Mesosphere

C

Troposphere

D

Thermosphere

6

What is the altitude range of the Troposphere?

A

0 - 12 km

B

12 - 50 km

C

50 - 85 km

D

85 - 120 km

7

In the Troposphere, temperature __________ with an increase in altitude.

A

increases

B

decreases

C

remains constant

D

first increases, then decreases

8

The temperature in the Troposphere decreases from 17°C to approximately what temperature?

A

-20°C

B

-58°C

C

-93°C

D

2°C

9

Which atmospheric layer contains the ozone layer?

A

Troposphere

B

Mesosphere

C

Thermosphere

D

Stratosphere

10

What is the temperature trend in the Stratosphere as altitude increases?

A

It decreases

B

It remains constant

C

It increases

D

It fluctuates randomly

11

The temperature in the Stratosphere rises from -58°C to what approximate temperature?

A

-93°C

B

17°C

C

0°C

D

2°C

12

Which region of the atmosphere extends from 50 km to 85 km?

A

Troposphere

B

Stratosphere

C

Mesosphere

D

Thermosphere

13

In which layer does the temperature decrease to as low as -93°C?

A

Thermosphere

B

Stratosphere

C

Troposphere

D

Mesosphere

14

The presence of which gas in the Stratosphere is responsible for the temperature increase?

A

Oxygen

B

Nitrogen

C

Ozone

D

Carbon dioxide

15

What are the major constituents of the Troposphere by volume?

A

Ozone and Water Vapours

B

Nitrogen and Oxygen

C

Argon and Carbon Dioxide

D

Sulphur and Nitrogen oxides

16

At what rate does the temperature decrease per kilometre in the Troposphere?

A

2°C

B

4°C

C

6°C

D

8°C

17

The breakdown of ozone (O3) in the upper stratosphere produces diatomic oxygen (O2) and what else?

A

Monoatomic oxygen (O)

B

Nitrogen (N2)

C

Chlorine (Cl)

D

Hydrogen (H)

18

The formation of ozone from O2 and O is what type of reaction?

A

Endothermic

B

Exothermic

C

Neutral

D

Reversible

19

Waste or exhaust products from the combustion of fossil fuels are classified as what?

A

Secondary pollutants

B

Primary pollutants

C

Contaminants

D

Natural gases

20

Which of the following is an example of a secondary pollutant?

A

Sulphur dioxide (SO2)

B

Carbon monoxide (CO)

C

Sulphuric acid (H2SO4)

D

Nitric oxide (NO)

21

Which primary pollutants are the main cause of acid rain?

A

Oxides of carbon

B

Oxides of sulphur and nitrogen

C

Hydrocarbons

D

Ammonia

22

What is the major source of carbon oxides (CO and CO2) emissions?

A

Plant respiration

B

Decomposition of organic matter

C

Combustion of fossil fuels

D

Photosynthesis

23

Which gas forms a layer around the Earth and is essential for keeping it warm?

A

Oxygen

B

Nitrogen

C

Ozone

D

Carbon dioxide

24

The phenomenon where the Earth's atmosphere traps heat is called what?

A

Ozone depletion

B

Acid rain

C

The greenhouse effect

D

Photosynthesis

25

What is an effect of global warming mentioned in the text?

A

Decreased sea levels

B

Formation of the ozone layer

C

Melting of glaciers and icebergs

D

Increased agricultural productivity

26

Which gas is a highly poisonous air pollutant that binds strongly with haemoglobin?

A

Carbon dioxide (CO2)

B

Sulphur dioxide (SO2)

C

Ozone (O3)

D

Carbon monoxide (CO)

27

Catalytic converters in automobiles are used to convert carbon monoxide into what?

A

Carbonic acid

B

Carbon dioxide

C

Nitrogen gas

D

Ozone

28

What percentage of total SO2 is released by the combustion of coal and petroleum products?

A

20%

B

50%

C

80%

D

100%

29

Sulphur dioxide (SO2) is a colorless gas with what characteristic?

A

Pleasant smell

B

No smell

C

Irritating smell

D

Sweet smell

30

Naturally occurring nitric oxide (NO) is primarily produced by what?

A

Volcanic eruptions

B

Combustion of coal

C

Electrical lightening in air

D

Bacterial decay

31

What is the pH of normal, unpolluted rain water?

A

Around 4

B

5.6 to 6

C

Exactly 7

D

8 to 9

32

Acid rain is formed when the pH of rain water reduces to approximately?

A

6

B

5.6

C

4

D

7

33

Acid rain attacks which chemical compound present in marble and limestone?

A

Silicon dioxide

B

Calcium carbonate

C

Sodium chloride

D

Iron oxide

34

What heavy metal ion, leached by acid rain, is mentioned to clog the gills of fish?

A

Lead

B

Mercury

C

Chromium

D

Aluminium

35

The ozone layer is a concentration of ozone located in which atmospheric layer?

A

Troposphere

B

Mesosphere

C

Stratosphere

D

Thermosphere

36

The ozone layer protects Earth from which type of harmful solar radiation?

A

Infrared

B

Visible light

C

Microwaves

D

Ultraviolet

37

Which class of chemical compounds are the major cause of ozone layer depletion?

A

Hydrocarbons

B

Chlorofluorocarbons (CFCs)

C

Oxides of Nitrogen

D

Oxides of Sulphur

38

What is the name for the region in which the ozone layer depletes significantly?

A

Atmospheric window

B

Ozone hole

C

Ionosphere

D

Black spot

39

A single chlorine free radical from a CFC can destroy up to how many ozone molecules?

A

One hundred

B

One thousand

C

Ten thousand

D

Many lacs

40

Ozone depletion can increase the risk of which disease in humans?

A

Malaria

B

Diabetes

C

Skin cancer

D

Asthma

41

Which of the following is NOT listed as an effect of ozone depletion?

A

Disruption of the food chain

B

Increased infectious diseases like malaria

C

Climatic changes

D

Increased global warming

42

What is the approximate percentage of carbon dioxide in dry air?

A

0.93%

B

1.00%

C

0.03%

D

20.94%

43

Which atmospheric layer lies beyond the mesosphere?

A

Stratosphere

B

Troposphere

C

Thermosphere

D

Ozone Layer

44

The temperature in the thermosphere __________ with increasing altitude.

A

decreases

B

increases

C

stays constant

D

decreases then increases

45

Which substance is NOT a primary pollutant?

A

Ozone (O3)

B

Carbon Monoxide (CO)

C

Sulphur Dioxide (SO2)

D

Hydrocarbon (CH4)

46

Without the greenhouse effect, the Earth's average temperature would be about?

A

15°C

B

-20°C

C

0°C

D

100°C

47

Combustion of fossil fuels in internal combustion engines produces which pollutant from the air's nitrogen?

A

Ammonia (NH3)

B

Nitric Oxide (NO)

C

Dinitrogen Monoxide (N2O)

D

Nitrogen Trichloride (NCl3)

48

Where does the ozone layer exist within the stratosphere?

A

Lower stratosphere

B

Upper stratosphere

C

Mid stratosphere

D

Throughout the stratosphere

49

The process of burning solid waste at high temperatures (650°C to 1100°C) is called?

A

Composting

B

Landfilling

C

Recycling

D

Incineration

50

Which of the following is a harmful gas produced during incineration?

A

Oxygen

B

Nitrogen

C

Dioxins

D

Water vapour