pH Scale, indicator, pH indicator and pH meter MCQs || 10th Chemistry Chapter 10

pH Scale, indicator, pH indicator and pH meter MCQs || 10th Chemistry Chapter 10

1. Which ion concentration is the basis for the pH scale?
A) [OH⁻]
B) [H⁺]
C) [Na⁺]
D) [Cl⁻]

2. What is formed when bases react with acids?
A) Hydrogen gas
B) Salt and water
C) Carbon dioxide
D) Hydrochloric acid

3. What gas is liberated when alkalies react with ammonium salts?
A) Oxygen
B) Ammonia
C) Carbon dioxide
D) Nitrogen

4. Which alkali is used in alkaline batteries?
A) Sodium hydroxide
B) Calcium hydroxide
C) Potassium hydroxide
D) Magnesium hydroxide

5. What is the pH of a neutral solution?
A) 0
B) 7
C) 14
D) 10

6. What happens to the pH value of a solution as its acidity increases?
A) It increases
B) It decreases
C) It remains the same
D) It fluctuates

7. Which of the following indicators turns blue in alkaline solutions?
A) Litmus
B) Methyl orange
C) Phenolphthalein
D) Universal Indicator

8. What is the range of the pH scale?
A) 0 to 10
B) 1 to 14
C) 0 to 14
D) 1 to 7

9. Which of the following is a use of sodium hydroxide?
A) Soap manufacturing
B) Fertilizer production
C) Battery production
D) Antacid formulation

10. What color does phenolphthalein turn in strongly alkaline solutions?
A) Red
B) Blue
C) Yellow
D) Colorless

11. What do acidic solutions have in terms of pH?
A) Greater than 7
B) Equal to 7
C) Less than 7
D) Equal to 14

12. Which of the following is used to measure the pH of a solution?
A) Beaker
B) pH meter
C) Thermometer
D) Burette

13. Which compound has a pH less than 7?
A) Pure water
B) Sodium chloride
C) Hydrochloric acid
D) Sodium hydroxide

14. Which of the following does not form when alkalis react with heavy metal salts?
A) Water
B) Hydroxides
C) Salt
D) Ammonia

15. What is the color of litmus in acidic solutions?
A) Blue
B) Green
C) Yellow
D) Red

16. Which indicator is colourless in strongly acidic solutions?
A) Methyl orange
B) Litmus
C) Phenolphthalein
D) Universal Indicator

17. What is the main function of hydrochloric acid in the stomach?
A) To neutralize bases
B) To aid digestion
C) To kill bacteria
D) Both B and C

18. Which acid is a strong dibasic acid?
A) Hydrochloric acid
B) Sulphuric acid
C) Nitric acid
D) Acetic acid

19. What is the color of a universal indicator in a neutral solution?
A) Red
B) Green
C) Blue
D) Yellow

20. What happens to the pH scale as the concentration of hydrogen ions increases?
A) It decreases
B) It increases
C) It remains constant
D) It becomes unstable

21. How do you measure the pH using Universal Indicator?
A) By using a thermometer
B) By dipping a strip in the solution
C) By heating the solution
D) By adding water

22. Which of the following is a physical property of bases?
A) Sour taste
B) Bitter taste
C) Sticky texture
D) Foul smell

23. Which of the following substances can neutralize acidity in the stomach?
A) Sodium hydroxide
B) Magnesium hydroxide
C) Calcium carbonate
D) Ammonium hydroxide

24. What is produced when acids react with carbonates?
A) Water
B) Carbon dioxide
C) Hydrogen
D) Salt

25. What happens to the pH of a solution when a base is added?
A) It becomes acidic
B) It becomes neutral
C) It increases
D) It decreases

26. What pH value indicates a strong acid?
A) 1
B) 7
C) 14
D) 10

27. Which of the following is an example of a strong acid?
A) Acetic acid
B) Sulphuric acid
C) Carbonic acid
D) Phosphoric acid

28. Which indicator is red at pH values below 4?
A) Litmus
B) Methyl orange
C) Phenolphthalein
D) Universal Indicator

29. What is the purpose of using a pH meter?
A) To heat solutions
B) To measure temperature
C) To measure pH accurately
D) To mix solutions

30. What does the sum of pH and pOH equal at 25 °C?
A) 10
B) 12
C) 14
D) 16


Correct Answers

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

Leave a Comment

Your email address will not be published. Required fields are marked *