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Environmental Chemistry MCQs and Answers with explanation

Environmental Chemistry MCQs and Answers with explanation

1. Air is polluted by





... Answer is d)
Explanation: Any substance that is present in air and has adverse effect on a part of atmosphere is known as air pollutant. Examples of air pollutant are toxic material, toxic gases and hydrocarbon. Hydrocarbons are considered as major source of air pollution due to their incomplete combustion.

2. Which of the following gas in not pollutant?





... Answer is c)
Explanation: CO2 is not considered as air pollutant as human exhale it and plants inhale it and utilize it for photosynthesis. Although, its excessive amount causes global warming, yet it is not known as air pollutant.

3. Oxides of sulfur and nitrogen react with oxygen to form





... Answer is b)
Explanation: Oxides of sulfur and nitrogen reaact with oxygen and water to form acids. For example SO2 and NO2 reacts with oxygen and water to produce H2SO4 and HNO3, respectively. These acids add up to rain water and causes acidic rain.

4. Oxidizing smog consists of high concentration of as





... Answer is b)
Explanation: Photochemical smog is formed due to reaction of sunlight with nitrogen oxides and hydrocarbons. As it contains high concentration of oxidant, ozone so it is also termed as oxidizing smog.

5. Thickness of ozone is





... Answer is b)
Explanation: Thickness of ozone ranges from 25 to 28 km.

6. Ozone is destroyed by


... Answer is c)
Explanation: CFCs are used in refrigerators, room air conditioner and aerosol cans. These gases are highly volatile and do not react with other compounds in troposphere.These gases diffuse into stratosphere where these molecules generate free chlorine radicals in presence of UV radiations. These free chlorine radicals react with ozone to form chlorine monoxide and oxygen gas. ClO further react with atomic oxygen produced during breaking of ozone molecule.

7. In leather industry





... Answer is b)
Explanation: In leather industry chromium (iii) is used in the form of chromium sulphate to stablize the leather( tan). Chromium (iii) is not considered as risk. Chromium (VI)is not used in leather manufacturing process. However it is produced from oxidation Cr(III) under certain conditions. Chromium in this state is high dangerous to anybody who comes incontact with it.

8. Water is purified by?





... Answer is d)
Explanation: Water is purified by aeration, coagulation and disinfaction with chlorine.

9. The Ecosystem is the smaler unit of





... Answer is a)
Explanation: The Ecosystem is a community or group of living organism that interact with each other in a particular environment.For example, tropical forests are ecosystems of trees, plant, birds, animals and microorganisms that are in constant interaction with each other. Biosphere comprises of all kinds of ecosystems. It includes both non living (water, sunlight) and living things.

10. When chlorine is passed through water then the disinfection is done due to the production of





... Answer is b)
Explanation: when Cl2 reacts with water, hypoclorous acid (HOCl) is produced. HOCl easily penetrates the cells and inhibit the growth of pathogenic microorganims. It is quit safe and naturally exist in humame bodies.

11.Peroxyacetylene (PAN) is an irritant to humane beings and its affects





... Answer is a)
Explanation: Peroxyacetylene (PAN) is an irritant to humane beings and its affects eyes.

12. Fungicides are the pesticides which





... Answer is a)
Explanation: Fungicides are the pesticides which controlls the growth of fungus.


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