Tag: constituents of air

Questions Related to constituents of air

The surface of the earth has_______of its total area as water.

chemistry air and atmosphere natural cycles and resources constituents of air component of air - nitrogen

  1. two-thirds

  2. one-thirds

  3. two-fifths

  4. one-tenths

Show answer
Correct Option: A
Explanation:

About $71\%$ of earth's surface is covered by water.

Oceans hold about $96.5\%$ of all earth's water.
The surface of the earth has two-thirds of its total area as water.

Which of following statements is true?

chemistry air and atmosphere natural cycles and resources constituents of air component of air - nitrogen

  1. The salinity of rivers increases with time

  2. The salinity of rivers decreases with time

  3. The salinity of seas increases with time

  4. The salinity of seas decreases with time

Show answer
Correct Option: C
Explanation:

A falling of rain on earth causes breaking up of rocks and transferring their minerals to the ocean, the ocean becomes saltier and by evaporation, water evaporates leaving salt in the oceans.


So, by this, we can say that salinity of increases with time.

Hence, the correct option is $\text{C}$

Almost all the water on the earth is contained in the:

chemistry air and atmosphere natural cycles and resources constituents of air component of air - nitrogen

  1. seas and oceans

  2. rivers, lakes, ice caps

  3. as ground water and in the atmosphere

  4. all of these

Show answer
Correct Option: D
Explanation:

Almost all the water on the earth is contained in the oceans, seas, rivers, lakes, ice caps, as ground water and in atmosphere as water vapour.

Option (D) is the correct answer.

The main source of water for perennial rivers is in the form of:

chemistry air and atmosphere natural cycles and resources constituents of air component of air - nitrogen

  1. lakes

  2. rain water

  3. snow

  4. dams

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Correct Option: C
Explanation:

Perennial rivers flows continuously throughout the year irrespective of seasons. Mostly they originates from the mountain and water is fed by melting of glaciers. These river get water by rain in rainy season, melting of ice in summer and by snow in winter.

Which of the following elements would give water on burning?

chemistry air and atmosphere natural cycles and resources constituents of air component of air - nitrogen

  1. Hydrogen

  2. Oxygen

  3. Carbon

  4. Nitrogen

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Correct Option: A
Explanation:

In a flame of pure hydrogen gas, burning in air, the hydrogen (H$ _2$) reacts with oxygen (O$ _2$) to form water (H$ _2$O) and releases energy. If carried out in atmospheric air instead of pure oxygen, as is usually the case, hydrogen combustion may yield small amounts of nitrogen oxides, along with the water vapour.


Hence, the correct option is $\text{A}$

By the process of infiltration ground water gets:

chemistry air and atmosphere natural cycles and resources constituents of air component of air - nitrogen

  1. cleared

  2. discharged

  3. recharged

  4. coloured

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Correct Option: C
Explanation:

Infiltration is the process by which water on the ground surface enters the soil. By this process ground water gets recharged.

All the plants require nitrogen for:

chemistry water and air and their importance natural cycles and resources constituents of air component of air - nitrogen

  1. reproduction

  2. photosynthesis

  3. transpiration

  4. growth

Show answer
Correct Option: D
Explanation:
All the plants require nitrogen for growth. Nitrogen is found in healthy soils and give plants the energy to grow and produce fruit or vegetables. Nitrogen is part of the chlorophyll molecule, which gives plant their green colour and is involved in  creating food for the plant through photosynthesis.
So, the correct answer is 'growth'

Gas used as a refrigerant is:

chemistry water and air and their importance natural cycles and resources constituents of air component of air - nitrogen

  1. Nitrogen

  2. Oxygen

  3. Hydrogen

  4. Water gas

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Correct Option: A
Explanation:

NITROGEN is used as a refrigerant. Nitrogen is a liquid at temperatures below 196.5 C and is used as a refrigerant for such things as preservation of blood and cooling of large computer systems, as well as some industrial uses. Being a liquid, it is more convenient to use for low temperature cooling than dry ice. Liquid nitrogen is also used in oil wells to build up pressure in order to force crude oil upward.

State True or False.
Nitrogen is a poisonous gas because animals die in its presence.

chemistry water and air and their importance natural cycles and resources constituents of air component of air - nitrogen

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

Nitrogen is not poisonous at normal atmospheric pressures.

Nitrogen is used in high-temperature thermometer :
chemistry water and air and their importance natural cycles and resources constituents of air component of air - nitrogen

  1. To prevent vaporization of mercury.

  2. To improve conductivity of mercury.

  3. To maintain mercury to remain in its state.

  4. To increase the specific heat capacity of mercury.

Show answer
Correct Option: A,C
Explanation:
The principle used to measure temperature is that of the apparent thermal expansion of the liquid. An inert gas is used for mercury intended to high temperature. The thermometer is filled with an inert gas such as argon or nitrogen above the mercury to reduce its volatilization.

Hence, both options (A) and (C) are correct.