Introduction, occurrence and physical properties of water

1. What percentage of the Earth’s water is found in oceans?
A) 50%
B) 97%
C) 70%
D) 25%

2. What is the freezing point of pure water at sea level?
A) 0°C
B) 100°C
C) 4°C
D) -10°C

3. Which two elements compose water?
A) Carbon and Oxygen
B) Oxygen and Hydrogen
C) Nitrogen and Hydrogen
D) Sulfur and Phosphorus

4. Water is known to be an excellent solvent for which type of compounds?
A) Only ionic compounds
B) Only molecular compounds
C) Both ionic and molecular compounds
D) None of the above

5. How much of the Earth’s total water is considered potable?
A) 1%
B) 0.5%
C) 0.2%
D) 2%

6. The maximum density of water is achieved at which temperature?
A) 0°C
B) 100°C
C) 4°C
D) 20°C

7. What is the boiling point of pure water at sea level?
A) 0°C
B) 50°C
C) 100°C
D) 212°C

8. Which property of water helps in maintaining the Earth’s temperature?
A) High surface tension
B) High heat capacity
C) Neutral to litmus
D) Colorless appearance

9. What is the primary source of water pollution in urban areas?
A) Agricultural runoff
B) Waste chemical dumps
C) Landfills
D) All of the above

10. Acid rain is formed by the combination of which pollutants?
A) CO2 and H2O
B) SO2 and NOx
C) H2SO4 and HNO3
D) All of the above

11. What does the term “hard water” refer to?
A) Water with a low pH
B) Water that contains high levels of minerals
C) Water that is unfit for drinking
D) Water with a high temperature

12. Which of the following can leach heavy metals into water supplies?
A) Acid rain
B) Ozone depletion
C) Incineration of waste
D) None of the above

13. What percentage of the human body consists of water?
A) 50%
B) 60%
C) 70%
D) 80%

14. Which property of water is responsible for its high capillary action?
A) Low surface tension
B) High boiling point
C) High surface tension
D) High density

15. What is the main component of industrial waste that affects water quality?
A) Organic waste
B) Heavy metals
C) Chemical pollutants
D) All of the above

16. Which disease can be caused by consuming polluted water?
A) Diabetes
B) Cancer
C) Waterborne diseases
D) Heart disease

17. What is the environmental significance of water?
A) It is used only for drinking.
B) It supports aquatic life.
C) It has no effect on weather patterns.
D) It is not essential for living organisms.

18. Which type of water is unfit for drinking and agricultural purposes?
A) Potable water
B) Groundwater
C) Sea water
D) Freshwater

19. What is the effect of acid rain on buildings made of marble and limestone?
A) They remain unchanged.
B) They get brighter.
C) They erode and get dull.
D) They become stronger.

20. What percentage of the world’s water is in the form of glaciers and ice caps?
A) 50%
B) 2%
C) 1%
D) 5%

21. Which of the following is a consequence of water pollution?
A) Increased water supply
B) Waterborne diseases
C) Improved water quality
D) None of the above

22. How does acid rain affect aquatic life?
A) It improves their habitat.
B) It causes suffocation in fish.
C) It has no effect on aquatic life.
D) It makes them thrive.

23. What type of water is characterized by high levels of dissolved minerals?
A) Soft water
B) Hard water
C) Distilled water
D) Pure water

24. What causes the acidification of rainwater?
A) Dissolved carbon dioxide
B) Air pollutants
C) Natural minerals
D) High temperatures

25. Which of the following is a property of pure water?
A) It has a pungent smell.
B) It is colored.
C) It is tasteless.
D) It is acidic.

26. What process does water undergo to become part of the atmosphere?
A) Filtration
B) Evaporation
C) Precipitation
D) Condensation

27. What is one way to eliminate temporary hardness of water?
A) Distillation
B) Boiling
C) Filtration
D) Ion exchange

28. What effect does high surface tension have on water?
A) It prevents it from freezing.
B) It allows small objects to float on its surface.
C) It increases its density.
D) It decreases its boiling point.

29. Which of the following is NOT a waterborne disease?
A) Cholera
B) Typhoid
C) Diabetes
D) Dysentery

30. Which water property helps in the survival of land plants?
A) High density
B) High heat capacity
C) Capillary action
D) Neutral to litmus

Answers

1. B
2. A
3. B
4. C
5. C
6. C
7. C
8. B
9. D
10. B
11. B
12. A
13. C
14. C
15. D
16. C
17. B
18. C
19. C
20. B
21. B
22. B
23. B
24. B
25. C
26. B
27. B
28. B
29. C
30. C