Tag: chemistry

Questions Related to chemistry

The progressive warming up of the earth's surface is mainly due to :

chemistry pollution of air and water environmental impact: global warming green house effect geobiochemical cycle

  1. automobile exhaust

  2. blanketing effect of carbon dioxide in atmosphere

  3. reforestation

  4. thickening of ozone layer

Show answer
Correct Option: B
Explanation:

$CO _2$ goes in the atmosphere and make a thick layer, this layer allowes the light to enter into the atmosphere but do not allow it to exit, the heat get trapped into the atmosphere and leads to the warming up of the surface.

Widely distributed hydrocarbon in the atmosphere of earth is :

chemistry natural resources- air, water and land environmental impact: global warming green house effect geobiochemical cycle

  1. Butane

  2. Methane

  3. Smog

  4. PAN

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Correct Option: B
Explanation:

Methane is by far the most abundant hydrocarbon constituting about 40 to 80 % of total hydrocarbons present in the urban atmosphere.

 
Hydrocarbons predominate among the atmospheric pollutants because of their widespread use in fuels.

Therefore, option B is correct.

Green house effect of global warming causes:

chemistry natural resources- air, water and land environmental impact: global warming green house effect geobiochemical cycle

  1. rise in temperature of earth

  2. rise in pressure on earth

  3. decrease in oxygen content earths atmosphere

  4. decrease in $CO _{2}$ content

Show answer
Correct Option: A
Explanation:
A greenhouse gas is any gaseous compound in the atmosphere that is capable of absorbing infrared radiation, thereby trapping and holding heat in the atmosphere.

The progressive heating up of surface of the earth is earth is called green house effect or global warming.

CO$ _2$ and H$ _2$O block a part of the heat (IR) emitted by the earth & reflect back. Due to this earth surface gets heated up.
50% in CO$ _2$ content of air can increase the surface temperature of the earth by 3$^o$ C.
In addition to CO$ _2$ , the other green - house gases are CFCs (17%), O$ _3$ (18%), NO (4%), water vapour (2%).

Thus, the correct answer is option A. 

Global warming is due to greenhouse effect. The greenhouse gas include:

chemistry air and water pollution control environmental impact: global warming green house effect geobiochemical cycle

  1. $CO _2$

  2. Oxides of nitrogen

  3. Both a & b

  4. None of the above

Show answer
Correct Option: A
Explanation:

Global warming is due to Green Effect due to increase in the concentration of $CO _2$ by human activities like burning fossil fuels.

( Global warming in the overall temperature of the Earth's atmosphere due to the greenhouse effect caused by the increased levels of $CO _2,CFCs$ and other pollutants. )

Green house effect can be reduced by:

chemistry natural resources- air, water and land environmental impact: global warming green house effect geobiochemical cycle

  1. growing trees and forests

  2. use of faulty refrigerators

  3. burning of fossil fuels

  4. the use of natural gas

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Correct Option: A
Explanation:

By growing trees and foresets, we can reduce level of carbon dioxide in atmosphere so we can reduce green house effect.

If $CCl _{3}$F is present in the stratosphere, it will react with which of the following:
A) Ozone    B) $N _{2}$     C)$CO _{2}$

chemistry natural resources- air, water and land environmental impact: global warming green house effect geobiochemical cycle

  1. A

  2. B

  3. A & B

  4. C & A

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Correct Option: A
Explanation:

Chlorofluorocarbon causes depletion of ozone, so, $CCl _{3}F$ will react with ozone in the stratosphere.

On warming formic acid with ammoniacal silver nitrate, the product formed is 

chemistry air and water pollution control environmental impact: global warming green house effect geobiochemical cycle

  1. silver oxide

  2. metallic silver

  3. formaldehyde

  4. silver formate

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Correct Option: B

Greenhouse effect keeps the earth surface:

chemistry air and water pollution control environmental impact: global warming green house effect geobiochemical cycle

  1. cold at night

  2. dusty and cold

  3. warm at night

  4. moist

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Correct Option: C
Explanation:

Due to greenhouse effect, the sunlight that Earth gets in daytime is trapped inside the Earth's atmosphere and in night the same energy keeps the Earth's surface warm.

Carbon dioxide and methane are the two major components of greenhouse.

chemistry air and water pollution control environmental impact: global warming green house effect geobiochemical cycle

  1. True

  2. False

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Correct Option: A
Explanation:

$CO _2, CH _4, N _2O, CFCs$ and $CO$ are the greenhouse gases. They are good at trapping heat and led to the melting of glaciers.

What are the advantages of chlorofluorocarbons? 

chemistry air and water pollution control environmental impact: global warming green house effect geobiochemical cycle

  1. Excellent refrigerants

  2. Very good propellants

  3. Useful in firefighting

  4. All of the above

Show answer
Correct Option: D
Explanation:

The advantages of chlorofluorocarbons (CFCs) are given below: 

1. Excellent refrigerants: low boiling point, uncreative. 
2. Very good propellants: low toxicity
3. Useful in firefighting