Tag: water and air and their importance

Questions Related to water and air and their importance

To increase the percentage of oxygen in the atmosphere :

chemistry water and air and their importance importance of oxygen is air present everywhere around us? air as a natural resource

  1. plant more trees

  2. kill all living beings

  3. cut down trees

  4. protect animal life

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Correct Option: A
Explanation:
Planting more trees directly increases the oxygen amount by the process of photosynthesis which in turn increases the percentage of oxygen in the atmosphere.

Hence the option A is correct.

Plant consume ________ to make their own food.

chemistry water and air and their importance importance of oxygen is air present everywhere around us? air as a natural resource

  1. Oxygen

  2. Carbon dioxide

  3. Both A and B

  4. None of the above

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Correct Option: B
Explanation:

Plant consume carbon dioxide, water and other nutrients to make their own food.


The leaves contain a pigment called chlorophyll, which colours the leaves green. 


Chlorophyll can make food the plant can use from carbon dioxide, water, nutrients, and energy from sunlight. This process is called photosynthesis.


Hence the option B is correct.

Which of the following is incorrect regarding oxygen?

chemistry water and air and their importance importance of oxygen is air present everywhere around us? air as a natural resource

  1. Solid oxygen is blue.

  2. Oxygen gas is odorless.

  3. Oxygen is non-toxic.

  4. Liquid and solid oxygen are paramagnetic.

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Correct Option: C
Explanation:

Solid oxygen is a clear substance with a light sky-blue colour. Oxygen gas is a colourless gas without taste or odour. Oxygen toxicity is a condition that results from the harmful effects of breathing molecular oxygen $(O _2)$ at elevated partial pressures. This causes hyperoxia, an excess of oxygen in body tissues.

Something that is paramagnetic means that it is weakly attracted to the poles of a magnetic field but it itself does not retain any magnetic properties once it is beyond that magnetic field. Oxygen, no matter what its state, is paramagnetic.In solid and liquid oxygen, the magnetic effect is measurable but in a gas, the molecules of oxygen possess ample energy of motion to overcome the weak magnetic influence. 

Why was there no oxygen in the early atmosphere?

chemistry water and air and their importance importance of oxygen is air present everywhere around us? air as a natural resource

  1. No water

  2. No animals

  3. No vegetation

  4. No fire

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Correct Option: C
Explanation:

Oxygen is produced by plants by the process of photosynthesis,

earlier there were no plants and vegetation, thats why no oxygen in the early atmosphere. 

Which of the following plays a very important role in the oxygen cycle?

chemistry water and air and their importance importance of oxygen is air present everywhere around us? air as a natural resource

  1. Birds

  2. Animals

  3. Plants

  4. Soil

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Correct Option: C
Explanation:

Plants plays a very important role in the oxygen cycle as plants create the majority of oxygen we breathe through the process of photosynthesis. In this process plants use $CO _2,$ sunlight and water to create energy. In this process they also create oxygen which they release into the air.

Plants also consumes ________ for respiration.

chemistry water and air and their importance importance of oxygen is air present everywhere around us? air as a natural resource

  1. Carbon dioxide

  2. Oxygen

  3. Nitrogen

  4. Both A and B

Show answer
Correct Option: B
Explanation:

Plants also consume oxygen for respiration.


At night, when photosynthesis can’t take place, plants continue to consume oxygen but they don’t release any back into the atmosphere.


As the amount of oxygen consumes by the plants is very low during respiration so it doesn't effect the oxygen levels of the atmosphere.


Hence the correct option is B.

Heavy water violence is formed on combining deuterium with ___________ .

chemistry water and air and their importance importance of oxygen is air present everywhere around us? air as a natural resource

  1. heavy isotope of oxygen only

  2. oxygen

  3. ammonia

  4. nitrogen

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Correct Option: B
Explanation:

Heavy water violence is formed on combining deuterium with oxygen.

Air is an example of __________.

water and air and their importance natural resources- air, water and land air around us air chemistry

  1. gas solid solution

  2. gas gas solution

  3. solid solid solution

  4. solid gas solution

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Correct Option: B
Explanation:

Air is a mixture of gases. So, solute and solvent both are gases.

hence, air is known as gas gas solution.

Which is a green house gas?
A) Methane 

B) Chlorofluorocarbons 
C) $CO _{2}$

water and air and their importance natural resources- air, water and land air around us air chemistry introduction to natural resources land

  1. $A$ and $B$

  2. $B$ and $C$

  3. $C$ and $D$

  4. $A, B$ and $C$

Show answer
Correct Option: D
Explanation:

Greenhouse effect
* The progressive heating up of surface of the earth is earth is called green house effect or global warming.
 $CO _2$ and $H _2O$ block a part of the heat (IR) emitted by the earth & reflect back. Due to this earth surface gets heated up.
 50% in $CO _2$ content of air can increase the surface temperature of the earth by $3^oC$.
* In addition to $CO _2$ , the other green - house gases are CFCs (17%), $O _3$ (18%), NO (4%), water vapour (2%).

Which of the following is not a sink for CO?

water and air and their importance natural resources- air, water and land air around us air chemistry introduction to natural resources land

  1. Haemoglobin

  2. Microorganims present in the soil

  3. Oceans

  4. None of the above

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Correct Option: A
Explanation:


* Incomplete combustion of fossil fuels liberate CO into air. 80% of CO is released from automobiles.


* Permissible level of CO in air is 9 ppm. It reduces $O _2$ supply in human by forming a stable carboxyhaemoglobin.

$2C+O _2\rightarrow 2CO$
$2CH _4+3O _2\rightarrow 2CO+4H _2O$

* CO interacts with oxyhaemoglobin ($O _2Hb$) and forms carboxyhaemoglobin (CO-Hb) as :

$O _2Hb+CO\rightarrow COHb+O _2$

* CO has high affinity for haemoglobin than that of oxygen.

Therefore, option A is correct.