Air Around Us - Class 6 Chemistry - Extra Questions

The component of air used by green plants to make their food, is _________.

The component of air used by green plants to make food is $$\text{carbon dioxide}$$.


Make sentences using the given set of words.
Respiration, dissolved, animals, air, aquatic

Respiration in aquatic animals is done by dissolved air.


What is the source of carbon dioxide in air?

Human activities like burning of oil, coal, gas, and many other fuels, deforestation are the primary cause of increased carbon dioxide in air. Carbon dioxide is also produced by respiration process of plants and animals.


Which gas in the atmosphere is essential for respiration?

$$\text{Oxygen gas}$$ in the atmosphere is essential for respiration.


A list of words is given. Use appropriate words to fill up the blanks in the following statement 

The ______ makes the windmill rotate.
(Air, oxygen, wind, water vapor, mixture, combination, direction, road, bottles, cylinders)

The answer is $$\text{wind}$$. 
The $$\text {wind}$$ makes the windmill rotate. The windmill is used to draw water from tube wells and to run floor mills. Windmills are also used in generating electricity.


Mention two uses of the following gas:
(I) Oxygen

The main two uses of oxygen gas are as follow:
1. It is used by all living beings for breathing. 
2. It is important for combustion. 


Name a process by which oxygen in the atmosphere is replaced.

Photosynthesis is the process that replaces oxygen in the atmosphere. In this process, plants make their own food and oxygen is produced along with it.


A list of words is given. Use appropriate words to fill up the blanks in the following statement.

 Air is a ______ of different gases.
( Air, oxygen, wind, water vapour, mixture, combination, direction, road, bottles, cylinders)

Air is a mixture of different gases. 
The composition of air is not uniform. It contains different gases that can be separated by physical methods and, so air is a mixture.


The balance of oxygen and carbon dioxide is maintained in the atmosphere. Explain.

Oxygen is needed for survival for most living beings. For example, we breathe in oxygen. Even plants take in oxygen through the process of respiration. At the same time, we exhale carbon dioxide. Plants on the other hand produce oxygen through photosynthesis while taking in carbon dioxide. So, there is a consumption and release of oxygen, and a consumption and release of carbon dioxide. This balance helps animals and plants survive.


Write just a few sentences for an imaginary situation if the following gas disappear from the atmosphere.
Oxygen

If there is no oxygen in the atmosphere then-
i. Earth will be lifeless as oxygen keeps animals and plants alive. We need oxygen for respiration.
ii. In absence of oxygen, combustion will be impossible.


Name two important processes supported by oxygen present in air.

Two processes supported by oxygen present in air:
1. Combustion (burning of a fuel)
2. Respiration (intake of oxygen by living beings for survival)


Explain the following observations very briefly.
The arrow of weathercock points towards a particular direction at a particular moment.

A weathercock is an instrument that indicates the direction of the wind. Its parts are- an arrow that is mounted at its center of gravity for it to move freely about a vertical axis.
The arrow of weathercock points towards a particular direction at a particular moment as it shows the direction in which air is moving at that place at a particular moment.


Match the items of column I with the items of column II
Column IColumn II
(a)Weather cock(i)Gases and fine dust particles
(b)Montaineers(ii)Sailing yacht
(c)Fine hair inside the nose(iii)Oxygen cylinders
(d)Smoke(iv)Direction of air flow
(e)Wind(v)Prevent dust particles

Correct matches are-
a) Weathercock - (iv) Direction of airflow.
b) Mountaineers - (iii) Oxygen cylinders.
c) Fine hair inside the nose - (v) Prevent dust particles.
d) Smoke - (i) Gases and fine dust particles.
e) Wind - (ii) Sailing yacht.


What would have happened if there would have been no atmosphere around the earth?

Without the atmosphere, life would not be possible as the atmosphere protects us from harmful gases. We could not live without air present in the atmosphere. In absence of the atmosphere, the earth would get so cold at night that we would not be able to survive. No $$CO_{2}$$ and $$N_{2}$$ gas present for plants without atmosphere.


Briefly state the importance of oxygen.

1. Oxygen is used by every living being for breathing and respiration.

2. Oxygen is necessary for burning.

3. Used as a fuel along with hydrogen in space programs.


Briefly state the importance of the following constituents of air:
(a) Oxygen, 
(b) Nitrogen, 
(c) Carbon dioxide, 
(d) Water vapor.

(a) Oxygen in the air is essential for respiration and burning. 
(b) Nitrogen dilutes the activity of oxygen in the air. Its compounds are very useful for the growth of plants. 
(c) Carbon dioxide acts as a food for plants and in the regeneration of oxygen. It also helps in trapping heat radiations on earth. 
(D) Water vapor controls climatic conditions and is very essential for the health and comfort of all living beings. 


What is the importance of water vapour in air ?

The significance of water vapour in the atmosphere is as follows:
1. Presence of water vapour in the air determines the climatic conditions. It also produces snow, fog, mist, hails and other phenomena, depending upon the temperature.
2. The presence of water vapour controls the rate of evaporation from plants and animals. 
3. The presence of water vapour is very essential for the growth of plants.
4. It is very essential for the health and comfort of animals.


State two important uses of oxygen.

Uses of oxygen: 
∙∙ It is essential for respiration in plants and animals.
∙∙ It is essential for the combustion of fuels.


Fill in the blanks:

Oxygen is collected by the ________ displacement of _______ .

Oxygen is collected by the downward displacement of water.


What problems are caused by the presence of dust particles in excessive amounts in the air? 

Excess of dust particles can cause serious respiratory problem. They also cause irritation to the eyes, throat and skin.


What problem is caused by the presence of the excessive amount of smoke particles in the air?

Smoke contains a few gases and fine dust particles and is often harmful. Excess of smoke particles in air can cause serious respiratory problems.


Give three uses of oxygen.

1. Oxygen is used by every living being for breathing and respiration.

2. Oxygen is necessary for burning.

3. Used as a fuel along with hydrogen in space programs.


Explain why:
Air dissolved in water contains a higher proportion of oxygen.

Air consists of $$78\%$$ nitrogen and $$21\%$$ oxygen. But oxygen dissolves in water easily than Nitrogen and any other component of air. Hence, water contains a higher portion of oxygen than nitrogen and others.


Match the following correctly :

  Group A  Group B
 (1) Oxygen gas (i) Inert gas
 (2) Carbon dioxide gas (ii) Support of combustion
 (3) Hydrogen gas (iii) Extinguishing fire gas
   (iv) Combustible gas

Group A                                        Group B
Oxygen gas                                 Support of combustion
Carbon dioxide gas                     Extinguishing fire gas
Hydrogen gas                             Combustible gas



Classify the following substance into elements, compounds or mixtures:
  • Smoke

The burning of fuel produces smoke. Smoke contains a few gases and fine dust particles. So smoke is a mixture.


What are the various components of air? Discuss.

Air contains mostly nitrogen and oxygen. In fact, these two gases together make up 99% of the air. The remaining 1% is constituted by carbon dioxide and a few other gases and water vapour.


Mention the gases present in the air along with their percentage composition.


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What do know about the presence of oxygen on earth?


From the table we have understood that the level of oxygen is very high in nature.

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Write down the uses of the following:

(I) Nitrogen gas.

  • It is used to prepare chemicals like ammonia, nitric acid, urea, etc.
  • It is used to prepare an inert atmosphere.
  • It is used to decrease the reactivity of oxygen in the air.
  • It is used to create unnatural smoke in films and dramas.


State a reason. Why there is a balance in the amount of carbon dioxide in the air, even though carbon dioxide is released into the atmosphere by various processes?

In photosynthesis, green plants manufacture their own food by absorbing carbon dioxide in the air and make food in the presence of chlorophyll and sunlight. Oxygen is released into the atmosphere, which maintains the composition of air and does not increase the amount of carbon dioxide in the air.

$$Carbon dioxide + Water \xrightarrow[chlorophyll]{sunlight} Carbohydrates + Oxygen$$


How will you prove that soil contains air in it?

Take a glass beaker  add some soil in it, then pour some water on the soil slowly, the air-bubbled comes out of the soil. This proves that soil holds air in it.


Class 6 Chemistry Extra Questions