An increase in $${ CO }_{ 2 }$$ concentration in the atmosphere will result in:

genetic disorders in plants and animals

MCQ Questions for Class 8 Chemistry Pollution Of Air And Water Quiz 3

The sources of air pollutants are:

0%
factories
0%
power plants
0%
automobile exhaust
0%
All of the above

A pond contains clean water. Which of the following activities will produce least pollution of water?

0%
Washing clothes in the pond
0%
Animals bathing in the pond
0%
Washing motor vehicles in the pond
0%
Swimming in the pond

Trees help in reducing the pollution of our environment. Lakhs of trees are planted by people in July every year. The occasion is called ______________.

0%
Forest Conservation Day
0%
Plantation month
0%
Van Mahotsav
0%
Wildlife week

The phenomenon of marble cancer is due to:

0%
global warming
0%
CFCs
0%
fog
0%
acid rain

Boojho wishes to contribute to reducing air pollution. Which vehicle should be used for going to school?

0%
Car
0%
School bus
0%
Auto rickshaw
0%
Scooter

Incomplete combustion of fuel such as petrol and diesel gives:

0%
nitrogen oxide
0%
sulphur dioxide
0%
carbon monoxide
0%
carbon dioxide

Potable water is the water which is

0%
obtained from a river.
0%
obtained from a lake.
0%
pure and fit for drinking.
0%
used only for washing clothes.

Which one of the following is a man-made source of air pollution?

0%
Volcanic-eruption
0%
Automobile-exhaust
0%
Both A and B
0%
None of these

Water is often treated with chlorine to ________.

0%
increase oxygen content
0%
kill germs
0%
remove suspended particles
0%
remove hardness

Which among the following is a major cause of water pollution?

0%
Fly ash
0%
Aeroplane
0%
Automobile exhaust
0%
Pesticides

Greenhouse effect keeps the earth surface:

0%
cold at night
0%
dusty and cold
0%
warm at night
0%
none of these

Air has________ composition with________ oxygen at high attitudes.

0%
fixed, less
0%
variable, less
0%
variable, more
0%
fixed, more

Incomplete combustion of petrol or diesel oil in automobile engines can be best detected by testing the fuel gases for the presence of __________.

0%
carbon monoxide and water vapour
0%
carbon monoxide
0%
nitrogen dioxide
0%
sulphur dioxide

Which of the following is one of the major factors that cause water pollution?

0%
Burning of fossil fuels.
0%
Dumping of industrial waste.
0%
Use of CFC's.
0%
None of these

If water pollution continues at its present rate, it will eventually:

0%
stop water cycle
0%
prevent precipitation
0%
make oxygen molecules unavailable to water plants
0%
make nitrate molecules unavailable to water plants

Explanation

If water pollution continues at its present rate, it will eventually make oxygen molecules unavailable to water plants and kill them.

Also, it kills life that depends on water bodies. Dead fish, crabs, birds, seagulls, dolphins, and many other animals often wind up on beaches, killed by pollutants in their habitat (living environment).

Option

C

$C$ is correct.

Which of the following is the main factor of water pollution?

0%
Smoke
0%
Industrial waste
0%
Detergents
0%
Ammonia

We feel fresh while on a morning walk in natural surroundings. Why don't we feel the same after 10 a.m and during rush hours?

0%
Partial burning of carbon by traffic which produced carbon monoxide.
0%
Inhaling polluted air makes us feel tired.
0%
More pollution produced during the day due to moving vehicles and industrial activities.
0%
All of the above.

Air is said to be a mixture because air at different places contains different amounts of various gases.

0%
True
0%
False

Explanation

Mixtures are formed when different substances are mixed in any proportion. Air contains different gases. The gases in the air are mainly nitrogen, oxygen, and a small amount of carbon dioxide and other gases. The amount of these gases is not fixed and can vary from place to place. For example, in an industrial area, the amount of

C O_{2}

$CO_2$ will be more due to pollution. Thus air is a mixture as its composition differs.

Which of the following options is a major water pollutant nowadays?

0%
Industrial effluents and waste
0%
Agricultural waste
0%
Domestic waste
0%
None of the above

Greenhouse effect is mainly caused by :

0%
$NO_2$
0%
$CO$
0%
$NO$
0%
$CO_2$

Explanation

The man-made component of the greenhouse effect is caused by man’s activities that emit greenhouse gases into the atmosphere. The most important of these is the burning of fossil fuels. Fossil fuels contain carbon, and when they are burnt this carbon combines with oxygen in the atmosphere to form carbon dioxide.

So, the greenhouse effect is mainly caused by

C O_{2}

$CO_2$ . Some other gases are also responsible for the greenhouse effect but carbon dioxide has a major contribution to it.

Hence, option

D

$D$ is correct.

Above figure represents the phenomenon of:

0%
Acid rain
0%
Greenhouse effect
0%
Ozone depletion
0%
None of these

An increase in

{C O}_{2}

${ CO }_{ 2 }$ concentration in the atmosphere will result in:

0%
acid rain
0%
global warming
0%
genetic disorders in plants and animals
0%
no effect on earth's climate

Explanation

C O_{2}

$CO_2$ is a greenhouse gas. Greenhouse gases are responsible for trapping the heat in the earth's atmosphere. The heat trapped helps in maintaining the temperature on the earth. But, an increase in the concentration of

C O_{2}

$CO_2$ on earth will cause more heat to be trapped in the atmosphere. As a result, the temperature of the earth will increase, and this is called global warming. Option B is correct.

The correct ascending order of gases as per their composition in air is:

0%
oxygen < carbon dioxide < nitrogen
0%
hydrogen < oxygen < nitrogen
0%
nitrogen < hydrogen < oxygen
0%
oxygen < carbon dioxide < hydrogen

Explanation

By volume dry air contains

78.09 %

$78.09\%$ Nitrogen,

20.95 %

$20.95\%$ Oxygen,

0.93 %

$0.93\%$ Argon,

0.03 %

$0.03\%$ Carbon dioxide and small traces of other gases. There is a small amount of hydrogen gas in the Earth's atmosphere; it makes up less than one part per million.

Ascending order of gases as per their composition in air is:

Hydrogen

<

$<$ Oxygen

<

$<$ Nitrogen

Carbon particles and smoke from factories:

0%
increase the rate of respiration in plants.
0%
decrease the rate of photosynthesis in plants.
0%
increase the absorption of carbon dioxide by plants.
0%
decrease the rate of transpiration in plants.

Explanation

Atmospheric pollutants like carbon particles and smoke from factories harm the plants. They can have direct toxic effects, or indirectly by changing soil $pH$ followed by solubilization of toxic salts of metals like aluminum. The particular matters have a negative mechanical effect. They cover the leaf blade reducing light penetration and blocking the opening of stomata. These impediments influence the process of photosynthesis whose rate declines sharply.

Option B is correct.

The pie chart shows the composition of air. Identify the gases W, X, Y.

0%
Nitrogen - Rare gases - Oxygen
0%
Carbon - Oxygen - Rare gases
0%
Nitrogen - Oxygen - Rare gases
0%
Rare gases - Hydrogen - Oxygen

The gas associated with the greenhouse effect is:

0%
carbon dioxide
0%
oxygen
0%
nitrogen dioxide
0%
sulphur dioxide

Explanation

Carbon dioxide

(C O_{2})

$(CO_2)$ is the primary greenhouse gas emitted through human activities.

Which of the following does not cause any kind of pollution?

0%
Establishing forest reserves
0%
Using pesticides in farms
0%
Developing housing estates
0%
All of these cause pollution

Which of the following is not a direct cause of air pollution?

0%
Thinning of the ozone layer
0%
Increase in the number of diabetic patients
0%
Destruction of habitats
0%
Global warming

Explanation

Air pollution leads to thinning of the ozone layer.

Destruction of aerial habitats and global warming takes place in air pollution.

But the increase in the number of diabetic patients does not take place due to air pollution.

Hence, the correct option is

B

$\text{B}$

The gases released from vehicle exhausts are:
I. Carbon monoxide
II. Sulphur dioxide
III. Oxides of nitrogen

0%
I and II only
0%
I and III only
0%
II and III only
0%
I, II and III

The earth reflects .......... energy into atmosphere.

0%
light
0%
heat
0%
hydro
0%
wind

CBSE Questions for Class 8 Chemistry Pollution Of Air And Water Quiz 3 - MCQExams.com

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Practice Class 8 Chemistry Quiz Questions and Answers

CBSE Questions for Class 8 Chemistry Pollution Of Air And Water Quiz 3 - MCQExams.com

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Practice Class 8 Chemistry Quiz Questions and Answers

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