Practice MCQ Questions and answers on Chemistry-GK

71

Which of the following chemical materials is responsible for the depletion of ozone layer in the atmosphere ?

A) Nitrous oxide B) Carbon dioxide C) Chlorofluorocarbon D) Sulphur dioxide

Discuss

Answer & Solution

Answer: Option C

Solution:

Chlorofluorocarbon is responsible for the depletion of ozone layer in the atmosphere.

72

Nitrogen fixation is a process of

A) Assimilation of nitrate B) Utilisation of nitrogen gas C) Conversion of organic nitrogen to proteins D) Conversion of molecular nitrogen to ammonia

Discuss

Answer & Solution

Answer: Option D

Solution:

Nitrogen fixation is the process by which atmospheric nitrogen is converted by either a natural or an industrial means to a form of nitrogen such as ammonia. In nature, most nitrogen is harvested from the atmosphere by microorganisms to form ammonia, nitrites, and nitrates that can be used by plants.

73

Greenhouse effect is caused by

A) Nitrogen B) Carbon dioxide C) Carbon monoxide D) Nitrogen dioxide

Discuss

Answer & Solution

Answer: Option B

Solution:

Earth's greenhouse gases trap heat in the atmosphere and warm the planet. The main gases responsible for the greenhouse effect include carbon dioxide, methane, nitrous oxide, and water vapour (which all occur naturally), and fluorinated gases (which are synthetic).

74

The lowest layer of earth's atmosphere is

A) Troposphere B) Stratosphere C) Mesosphere D) Ionosphere

Discuss

Answer & Solution

Answer: Option A

Solution:

This is the lowest part of the atmosphere.

75

Earth’s atmosphere is an envelope of gases extending to a height of

A) 100 km B) 150 km C) 200 km D) 300 km

Discuss

Answer & Solution

Answer: Option C

Solution:

The atmosphere of the Earth is an envelope of gases extending to a height of 200km.

76

Depletion of ozone layer causes

A) Blood cancer B) Lung cancer C) Skin cancer D) Breast cancer

Discuss

Answer & Solution

Answer: Option C

Solution:

Depletion of ozone layer causes skin cancer.

77

Nitrification is the biological process of converting

A) N₂ into nitrate B) N₂ into nitrite C) Ammonia into nitrite D) Ammonia into N₂

Discuss

Answer & Solution

Answer: Option C

Solution:

Nitrification is the biological process of converting ammonia into nitrite.

78

Besides CO₂, the other green house gas is

A) CH₄ B) N₂ C) Ar D) O₂

Discuss

Answer & Solution

Answer: Option A

Solution:

Besides CO₂, the other green house gas is methane (CH₄).

79

The greenhouse effect is caused by the higher level of which gas in the atmosphere ?

A) Carbon monoxide B) Carbon dioxide C) Nitrous oxide D) Sulphur dioxide

Discuss

Answer & Solution

Answer: Option B

Solution:

Carbon dioxide (CO₂) is the primary greenhouse gas emitted through human activities.

80

The atmospheric gas that is mainly responsible for green house effect :

A) Ozone B) Nitrogen C) Oxygen D) Carbon dioxide

Discuss

Answer & Solution

Answer: Option D

Solution:

The atmospheric gas that is mainly responsible for green house effect carbon dioxide.