Here’s a bank of 60 multiple-choice questions (MCQs) on the topic of water, tailored for a BISE Gujranwala audience. The questions are categorized into easy, moderate, and tough levels, with answers provided at the end.
### Easy Questions (30% - 18 Questions)
1. **What is the chemical formula of water?**
A) H2O
B) CO2
C) O2
D) H2
2. **Water is primarily found in which of the following states at room temperature?**
A) Solid
B) Liquid
C) Gas
D) Plasma
3. **Which of the following is a property of water?**
A) High boiling point
B) Low density
C) Non-polar
D) None of the above
4. **What is the main reason water is a good solvent?**
A) It has a high density.
B) It is non-polar.
C) It can dissolve many ionic and polar substances.
D) It has a low specific heat.
5. **Which bond is primarily responsible for water's unique properties?**
A) Ionic bond
B) Covalent bond
C) Hydrogen bond
D) Metallic bond
6. **What type of water contains dissolved minerals like calcium and magnesium?**
A) Pure water
B) Soft water
C) Hard water
D) Distilled water
7. **What causes temporary hardness in water?**
A) Magnesium sulfate
B) Calcium carbonate
C) Sodium chloride
D) Iron oxide
8. **Which method can be used to remove temporary hardness from water?**
A) Boiling
B) Filtration
C) Reverse osmosis
D) Distillation
9. **Which of the following is a disadvantage of hard water?**
A) It is good for drinking.
B) It can cause scale buildup in pipes.
C) It is soft to the touch.
D) It has a pleasant taste.
10. **What is a common source of domestic effluents?**
A) Factories
B) Farms
C) Sewage from households
D) Rivers
11. **Water is known as the universal solvent because it can dissolve:**
A) Only solids
B) Only gases
C) Many ionic and polar substances
D) Only liquids
12. **What is the primary cause of water pollution?**
A) Natural disasters
B) Human activities
C) Overpopulation
D) Weather changes
13. **What type of water has a high concentration of dissolved minerals?**
A) Soft water
B) Distilled water
C) Hard water
D) Rainwater
14. **Which of the following is an effect of water pollution?**
A) Improved biodiversity
B) Waterborne diseases
C) Increased fish populations
D) None of the above
15. **Which disease is primarily spread through contaminated water?**
A) Diabetes
B) Tuberculosis
C) Cholera
D) Hypertension
16. **What is the best way to prevent waterborne diseases?**
A) Boiling water
B) Drinking tap water
C) Adding sugar
D) None of the above
17. **What is a characteristic of soft water?**
A) High mineral content
B) Pleasant taste
C) Low soap lathering ability
D) Low hardness
18. **The presence of which gas in water indicates pollution?**
A) Oxygen
B) Carbon dioxide
C) Hydrogen sulfide
D) Nitrogen
### Moderate Questions (40% - 24 Questions)
19. **How does the polar nature of water affect its properties?**
A) It makes water a poor solvent.
B) It enhances water's ability to form hydrogen bonds.
C) It increases water's boiling point.
D) It decreases water's density.
20. **What is the main reason hard water is not suitable for washing?**
A) It produces more lather with soap.
B) It leaves soap scum.
C) It has a pleasant smell.
D) It is too soft.
21. **What is the term for the removal of hardness from water?**
A) Softening
B) Filtering
C) Boiling
D) Distillation
22. **Which method is commonly used to remove permanent hardness?**
A) Boiling
B) Ion exchange
C) Filtration
D) Freezing
23. **What is the effect of industrial effluents on water bodies?**
A) They improve water quality.
B) They can lead to an increase in aquatic life.
C) They can introduce toxic substances.
D) They have no significant impact.
24. **What is the main source of agricultural effluents?**
A) Sewage
B) Fertilizers and pesticides
C) Industrial waste
D) Stormwater runoff
25. **How does water pollution affect aquatic ecosystems?**
A) It has no effect.
B) It improves water quality.
C) It disrupts food chains and habitats.
D) It increases biodiversity.
26. **What is one method to test for water hardness?**
A) pH test
B) Conductivity test
C) Temperature test
D) Turbidity test
27. **Which of the following is a consequence of eutrophication in water bodies?**
A) Increased oxygen levels
B) Excessive algae growth
C) Decreased nutrient levels
D) None of the above
28. **Which water treatment process uses chlorine?**
A) Filtration
B) Disinfection
C) Sedimentation
D) Coagulation
29. **What is the primary use of sodium carbonate in water treatment?**
A) Softening water
B) Disinfecting water
C) Removing iron
D) Adjusting pH
30. **How can industrial effluents be treated before discharge into water bodies?**
A) By adding sugar
B) By using biological treatment methods
C) By boiling
D) None of the above
31. **What is the main source of heavy metals in water pollution?**
A) Agricultural runoff
B) Industrial discharge
C) Domestic waste
D) Atmospheric deposition
32. **What is one way to control waterborne diseases?**
A) Increasing water temperature
B) Improving sanitation and hygiene
C) Adding chemicals to water
D) Increasing water hardness
33. **Which of the following processes leads to the formation of hard water?**
A) Rainfall
B) Evaporation
C) Percolation through mineral-rich soils
D) Condensation
34. **What does the term "biochemical oxygen demand" (BOD) indicate?**
A) Amount of oxygen in the air
B) Rate of oxygen consumption by microorganisms in water
C) Amount of chlorine in water
D) Level of acidity in water
35. **What type of hardness is caused by calcium sulfate?**
A) Temporary hardness
B) Permanent hardness
C) Both A and B
D) None of the above
36. **Which pollutant is often found in agricultural effluents?**
A) Plastic waste
B) Pesticides
C) Heavy metals
D) Oil
37. **What is the effect of heavy metals in water?**
A) They enhance aquatic life.
B) They can be toxic to humans and wildlife.
C) They improve water quality.
D) They have no effect.
38. **What is the primary method for removing lead from contaminated water?**
A) Filtration
B) Reverse osmosis
C) Boiling
D) Chemical precipitation
### Tough Questions (30% - 18 Questions)
39. **Which of the following statements about hydrogen bonding in water is true?**
A) It is stronger than ionic bonds.
B) It is responsible for water's high specific heat.
C) It makes water a non-polar molecule.
D) It has no effect on water's properties.
40. **Which is NOT a consequence of excessive hard water use?**
A) Increased soap usage
B) Reduced efficiency of heating systems
C) Reduced mineral content in drinking water
D) Scale formation in pipes
41. **What is the primary challenge of removing nitrates from water?**
A) They are easily removed by boiling.
B) They are highly soluble and difficult to filter out.
C) They do not affect water quality.
D) They are only present in soft water.
42. **What does the presence of coliform bacteria in water indicate?**
A) Water is safe for drinking.
B) Possible fecal contamination.
C) High mineral content.
D) Presence of chlorine.
43. **What is the main focus of water quality monitoring?**
A) To enhance the taste of water
B) To ensure the water is free of chemical pollutants
C) To check the aesthetic quality of water
D) To reduce water hardness
44. **Which treatment method is most effective for removing phosphates from water?**
A) Chlorination
B) Chemical precipitation
C) Filtration
D) Boiling
45. **What is the most significant health risk associated with untreated water?**
A) Reduced oxygen levels
B) Waterborne diseases
C) Increased acidity
D) High mineral content
46. **Which of the following is a characteristic of oligotrophic water bodies?**
A) High nutrient levels
B) High productivity
C) Low nutrient levels
D) Polluted water
47. **What is the primary role of the Clean Water Act in Pakistan?**
A) To promote water conservation
B) To regulate water quality standards
C) To increase water supply
D) To promote industrial growth
48. **What is the significance of using activated carbon in water treatment?**
A) It softens water.
B) It removes dissolved organic matter and chlorine.
C) It increases water hardness.
D) It has no significance.
49. **Which of the following methods is used to treat wastewater?**
A) Desalination
B) Primary, secondary, and tertiary treatment
C) Reverse osmosis
D) None of the above
50. **Which factor is NOT a contributor to water scarcity?**
A) Population growth
B) Climate change
C) High rainfall
D) Pollution
51. **What is the purpose of using flocculants in water treatment?**
A) To increase water hardness
B) To aid in the sedimentation of suspended particles
C) To improve water taste
D) To sterilize water
52. **What does the term "turbidity" refer to in water quality?**
A) The acidity of water
B) The clarity of water
C) The temperature of water
D) The hardness of water
53. **What type of water treatment is most effective in developing countries for preventing waterborne diseases?**
A) Chemical treatment
B) Boiling
C) Filtration
D) Distillation
54. **What is the main benefit of rainwater harvesting?**
A) It decreases the risk of flooding.
B) It provides a sustainable source of freshwater.
C) It increases groundwater levels.
D) All of the above
55. **What is the consequence of high BOD levels in water bodies?**
A) Increased oxygen levels
B) Decreased aquatic life
C) Enhanced water clarity
D) Increased pH
56. **What type of water is most suitable for drinking?**
A) Distilled water
B) Hard water
C) Rainwater
D) Tap water
57. **What is the primary goal of wastewater treatment plants?**
A) To reduce the amount of water available for irrigation
B) To remove pollutants from wastewater before discharge
C) To enhance the taste of drinking water
D) To increase the temperature of water
58. **Which of the following is NOT a method of chemical water treatment?**
A) Chlorination
B) Ozonation
C) Sedimentation
D) Coagulation
59. **What does a high concentration of nitrates in drinking water indicate?**
A) Low water quality
B) High mineral content
C) Safe drinking conditions
D) Absence of pollutants
60. **Which waterborne disease is caused by the bacteria E. coli?**
A) Typhoid
B) Cholera
C) Dysentery
D) Hepatitis A
### Answers
1. A
2. B
3. A
4. C
5. C
6. C
7. B
8. A
9. B
10. C
11. C
12. B
13. C
14. B
15. C
16. A
17. D
18. C
19. B
20. B
21. A
22. B
23. C
24. B
25. C
26. B
27. B
28. B
29. A
30. B
31. B
32. B
33. C
34. B
35. B
36. B
37. B
38. B
39. B
40. C
41. B
42. B
43. B
44. B
45. B
46. C
47. B
48. B
49. B
50. C
51. B
52. B
53. B
54. D
55. B
56. A
57. B
58. C
59. A
60. C