Page 1 - HA

SAI International School
Subject - Chemistry
Class - VIII
Topic –Pollution of Air and water
Sub-Topic-Water Pollution and its causes

Home Assignment

Objective/MCQs

1. Which of the following disease cannot be caused by the drinking of river water
contaminated by untreated sewage?
a. Cholera.
b. Typhoid.
c. Tuberculosis.
d. Diarrhoea.
2. Eutrophication by sewage pollution refers to the
a. Nutrient enrichment of freshwater bodies.
b. Nutrient depletion of freshwater bodies.
c. Toxic chemical accumulation in freshwater bodies.
d. Heavy metal accumulation in freshwater bodies.
3. Pollution of water is responsible for
a. Oil refineries.
b. Sewage.
c. Pesticides.
d. All of the above.
4. What is the main cause of pollution of water?
a. Discharge of untreated sewage.
b. Bathing.
c. Discharge of industrial wastes.
d. Both a and c.

Subjective Type
Q. No. Questions Skill Marks
1. Which chemical if used excessivley in agriculture will cause U 1
death of aquatic animals due to oxygen deficiency?
2. Can we consider fly ash as the water pollutant? U 1

3. Choose the correct option from the following: U 1
(a) If both Assertion and Reason are correct and Reason is the
correct explanation of Assertion.
(b) If both Assertion and Reason are correct, but Reason is not
the correct explanation of Assertion.
(c) If Assertion is correct but Reason is incorrect.
(d) If Assertion is incorrect but Reason is correct.
(e) If Assertion & Reason both are incorrect.
Assertion (A): Fertilisers are water pollutants.
Reason (R): It provides nutrients for the algae to grow on water.
4. Write down the sources of water pollution. R 3

1