CBSE - Grade-8 - Chemistry - Chapter 18- Pollution Of Air And Water

Table of Contents - 

1. Air Pollution
2. Air Pollutants
3. Causes of Air Pollution
4. Natural Causes of Air Pollution
5. Effects of Air Pollution 

Answer the following questions:-

1. Which of the following is major source of water pollution?
   (a) Industrial wastes
   (b) Untreated sewage
   (c) Use of fertilisers
   (d) Toxic metals
2. _____ is a commonly used chemical method for purifying water.
   (a) Adding salt to water
   (b) Using water purifier
   (c) Filtration
   (d) Chlorination
3. Ganga Action Plan is associated with-
   (a) Increase of fish culture in the Ganges
   (b) Reduce Ganga water pollution
   (c) Construct more bridges over the Ganges
   (d) Increase water transport on the Ganges
4. Is clear, transparent water always fit for drinking? Comment.

Ans: No, The basic properties of Potable water are:

-> It should be Transparent, odourless and tasteless

-> It should have no SPM, germs and impurities

-> It should have some basic minerals required for our survival

-> It contain dissolved O2 and CO2 for survival of US and Aquatic Life

1. Why does the increased level of nutrients in the water affect the survival of aquatic organisms?

Ans: Eutrophication

1. Name three diseases caused by consuming polluted water.

Ans: Cholera, Typhoid and Dysentery

1. How does ground water get polluted? How is it harmful?
2. Can hot water be a pollutant? Explain.

Ans: Any substance that can harm living organisms and environment is called as a pollutant. Hot water when poured directly into lakes, ponds, streams etc can damage the Aquatic life of that water body due to abnormal / sudden change in temperature.

Specialization

CBSE Syllabus and NCERT Books

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