Class 11 Chemistry Environmental Chemistry Exam Questions

LEVEL -1

1.Name the region of atmosphere which contains Ozone layer?

Ans: Stratosphere.

2. Name the chemical responsible for acid rain?

Ans: Oxide of Sulphur , Oxide of Nitrogen.

3.What is CFC stand for ?

Ans: Chlorofluorocarbon or Freons.

4. Name the gases responsible for green house effect?

Ans: CO₂ ,CFC, Oxide of Nitrogen, Water vapours.

5. What is PAN.

Ans: Peroxyacyl nitrate, a toxic substance.

6. Name the sink of carbon dioxide in atmosphere.

Ans: Ocean and green plants.

LEVEL-2

1. Define environmental chemistry.

Ans: Environmental chemistry is defined as the branch of science which deals with chemical process occurring in the environment It involves the study of origin , Transport, reaction, effect of chemical species in the environment.

2. What do you mean by Biochemical Oxygen Demand (BOD)?

Ans: It is a measure of the dissolved oxygen that would be needed by micro-organisms and various pollutants.

3. What is eutrophication?

Ans: Eutrophication is the process of nutrient enrichment of water bodies and subsequent loss of biodiversity.

4. What is abbreviations FGD and CFC?

Ans: FGD means Fuel Gas Desulpherisation and CFC means Chloroflurocarbon.

5. How do pollutant and contaminant differ?

Ans: Pollutant is a substance already present in atmosphere which spoils the environment by its concentration due to human activities. Contaminant is a substance that does not occur in the nature but is introduced in significant amount into the atmosphere by human action or accidentally.

6. How can domestic waste be used as manure?

Ans: Domestic waste comprises of two types of materials, biodegradable such as leaves, rotten foods, etc, and non-biodegradable such as plastic, glass, metal scrap, etc , The non-biodegradable waste is sent to industry for recycling. The biodegradable waste should be deposited in the landfills. With the passage of time, it is converted into compost manure.

LEVEL 3

1.Explain giving reasons “ The presence of CO produce the amount of haemoglobin available in the blood for carrying oxygen to the body cells “ ?

Ans: CO combine with haemoglobin of the red blood corpuscles ( RBC ) about 200 times more easily than Oxygen to form carboxyhaemoglobin reversibly as follows ;

Hb + CO = HbCO

Thus it is not able to combine with oxygen to form oxy haemoglobin and transport of oxygen to different body cells cannot takes place.

2. Give three examples in which green chemistry has been applied?

Ans:

(a) In dry cleaning use of liquefied CO₂ in place of tetrachloroethene ( Cl₂C=CCl₂ )

(b) In bleaching of paper using H₂O₂ in place of chlorine.

(c) In the manufacture of chemicals like ethanol using environment friendly chemicals and conditions.

3. What is Pneumoconiosis? How does it occur?

Ans: Pneumoconiosis is a disease of lungs such as lung cancer, bronchital asthma, chronic bronchitis, etc. it is caused by small sized particulates which enter into lung through nose and provide a large surface area for adsorption of carcinogenic compounds such as polynuclear hydrocarbons, asbestos, etc.