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
- B
- B
- B
- C
- B
- B
- A
- C
- A
- D
- C
- B
- C
- A
- D
- C
- D
- B
- B
- A
- B
- B
- B
- B
- C
- A
- B
- B
- C
- C