Tag: chemistry

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Questions Related to chemistry

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

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

  1. automobile exhaust

  2. blanketing effect of carbon dioxide in atmosphere

  3. reforestation

  4. thickening of ozone layer
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

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

Widely distributed hydrocarbon in the atmosphere of earth is :

  1. Butane

  2. Methane

  3. Smog

  4. PAN
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

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

Green house effect of global warming causes:

  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
Reveal answer Fill a bubble to check yourself
A Correct answer
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. 
Multiple choice chemistry air and water pollution control environmental impact: global warming green house effect geobiochemical cycle

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

  1. $CO _2$

  2. Oxides of nitrogen

  3. Both a & b

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
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. )

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

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

  1. silver oxide

  2. metallic silver

  3. formaldehyde

  4. silver formate
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Formic acid acts as a reducing agent. When heated with ammoniacal silver nitrate (Tollens' reagent), it reduces silver ions to metallic silver, forming a silver mirror.

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

What are the advantages of chlorofluorocarbons? 

  1. Excellent refrigerants

  2. Very good propellants

  3. Useful in firefighting

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
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