How to purify water by boiling - Exam
  • 1. What is the primary purpose of boiling water for purification?
A) To remove sediment
B) To kill harmful microorganisms
C) To improve the taste
D) To add minerals
  • 2. At what temperature does water typically need to boil to be purified?
A) 100°C (212°F)
B) 75°C (167°F)
C) 150°C (302°F)
D) 50°C (122°F)
  • 3. How long should water be boiled to ensure effective purification?
A) 30 seconds
B) 1 minute
C) 5 minutes
D) 15 seconds
  • 4. In mountainous areas, should the boiling time be increased or decreased?
A) Depends on humidity
B) Increased
C) Stay the same
D) Decreased
  • 5. Why is longer boiling time required at higher altitudes?
A) Water boils at a higher temperature
B) Water boils at a lower temperature
C) The water is purer
D) The air is less dense
  • 6. What type of container is best for boiling water?
A) Stainless steel
B) Aluminum
C) Cardboard
D) Plastic
  • 7. What should you do before boiling water for purification?
A) Chill the water
B) Filter out sediment
C) Add sugar
D) Add salt
  • 8. Does boiling water remove chemical contaminants?
A) No
B) Yes, most of them
C) Yes, all of them
D) Yes, only chlorine
  • 9. What should you do after boiling the water?
A) Add lemon
B) Drink it immediately
C) Let it cool down
D) Add ice
  • 10. What organisms are effectively killed by boiling?
A) Microplastics
B) Heavy metals
C) Pesticides
D) Bacteria and viruses
  • 11. Can boiling water remove taste or odor issues?
A) No, never
B) Sometimes
C) Only bad odors
D) Yes, always
  • 12. What is the best way to store boiled water?
A) In direct sunlight
B) In an open container
C) In the refrigerator uncovered
D) In a clean, sealed container
  • 13. For how long is boiled water generally considered safe to drink?
A) 1 week
B) 1 month
C) 24 hours
D) Indefinitely
  • 14. What fuel source is suitable for boiling water?
A) Only gas
B) Only electricity
C) All of the above
D) Only wood
  • 15. How does water look when it's boiling?
A) Still and clear
B) Frothy on top
C) Bubbling vigorously
D) Steaming gently
  • 16. If you only have slightly cloudy water, is boiling enough?
A) Boiling is better after filtering
B) Cloudiness is irrelevant
C) No, it's not safe
D) Yes, boiling makes it safe
  • 17. What if the water source is suspected to be heavily contaminated with chemicals?
A) Boil it twice
B) Just boil it longer
C) Boiling will remove all contaminants
D) Boiling is not sufficient
  • 18. What does "purification" mean in the context of water?
A) Making it colder
B) Removing harmful substances
C) Changing the color
D) Adding flavors
  • 19. Does boiling soften hard water?
A) Partially
B) No, never
C) Makes it harder
D) Yes, completely
  • 20. Can you use a microwave to boil water for purification?
A) Yes, it's the best method
B) Only if it has a special setting
C) Yes, but it may not be as effective
D) No, never
  • 21. Why might microwave boiling be less effective?
A) Faster boiling
B) Uneven heating
C) It's more energy-efficient
D) Higher temperature
  • 22. What is the relationship between water hardness and boiling?
A) Hardness prevents boiling.
B) Boiling increases hardness.
C) Boiling reduces some hardness.
D) Boiling has no effect on hardness.
  • 23. What is the first step when purifying water from an unknown source?
A) Boil the water.
B) Filter the water.
C) Add chlorine.
D) Locate the water source.
  • 24. What is the most reliable method of making water safe to drink?
A) Adding iodine.
B) Multiple methods
C) Boiling alone
D) Filtering alone
  • 25. Which of the following is NOT removed by boiling water?
A) Viruses
B) Bacteria
C) Lead
D) Protozoa
  • 26. What is the purpose of letting boiled water cool before drinking?
A) Improve the taste
B) Add oxygen
C) Prevent burns
D) Increase purity
  • 27. What does vigorously boiling water mean?
A) Rolling boil
B) Completely evaporated
C) Gentle simmer
D) Just starting to steam
  • 28. Which of the following will help remove particulate matter from water before boiling?
A) Filtering the water
B) Freezing the water
C) Adding sugar to the water
D) Exposing the water to sunlight
  • 29. Why should you consider the source of the water?
A) Because all water tastes the same
B) Because all sources are equally safe
C) Source doesn't matter
D) To assess likely contaminants
  • 30. What's a portable water boiling device?
A) Shower head
B) Swimming pool
C) Garden hose
D) Camping stove
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