NCERT Book Class 10th SCIENCE MCQ
Chapter 2 : Acids, Bases and Salts
Multiple-Choice Questions (MCQs) with Answers
1. Which of the following is an organic acid?
(a) Hydrochloric acid
(b) Sulfuric acid
(c) Acetic acid
(d) Nitric acid
Answer: (c) Acetic acid
2. Blue litmus paper turns red in the presence of:
(a) Acid
(b) Base
(c) Salt
(d) Neutral solution
Answer: (a) Acid
3. What color does phenolphthalein indicator turn in a basic medium?
(a) Colorless
(b) Red
(c) Pink
(d) Blue
Answer: (c) Pink
4. Which of the following is not a natural indicator?
(a) Turmeric
(b) Litmus
(c) Methyl orange
(d) Hibiscus flower
Answer: (c) Methyl orange
5. The pH value of a neutral solution on the pH scale is:
(a) 7
(b) 0
(c) 14
(d) 10
Answer: (a) 7
6. The taste of an acid is:
(a) Bitter
(b) Sour
(c) Sweet
(d) Salty
Answer: (b) Sour
7. Bases dissolve in water to form:
(a) H⁺ ions
(b) OH⁻ ions
(c) Cl⁻ ions
(d) Na⁺ ions
Answer: (b) OH⁻ ions
8. Which of the following is a weak acid?
(a) HCl
(b) H₂SO₄
(c) CH₃COOH
(d) HNO₃
Answer: (c) CH₃COOH
9. The pH value of acid rain is:
(a) Less than 7
(b) 7
(c) More than 7
(d) 14
Answer: (a) Less than 7
10. Milk of magnesia is used as:
(a) An acid
(b) An alkaline antacid
(c) A salt
(d) A neutral solution
Answer: (b) An alkaline antacid
11. The reaction between an acid and a base is called:
(a) Neutralization
(b) Oxidation
(c) Reduction
(d) Combination
Answer: (a) Neutralization
12. In the reaction NaOH + HCl → NaCl + H₂O, the salt formed is:
(a) Sodium chloride
(b) Sodium hydroxide
(c) Hydrochloric acid
(d) Water
Answer: (a) Sodium chloride
13. What is used to neutralize excess acid in the stomach?
(a) Antacid
(b) Aspirin
(c) Vitamin
(d) Salt
Answer: (a) Antacid
14. Which gas is released when a metal carbonate reacts with an acid?
(a) Hydrogen
(b) Oxygen
(c) Carbon dioxide
(d) Nitrogen
Answer: (c) Carbon dioxide
15. Which gas is released when an acid reacts with a metal?
(a) CO₂
(b) H₂
(c) O₂
(d) N₂
Answer: (b) H₂
16. The chemical formula of baking soda is:
(a) NaHCO₃
(b) Na₂CO₃
(c) NaOH
(d) NaCl
Answer: (a) NaHCO₃
17. The formula of Plaster of Paris is:
(a) CaSO₄·2H₂O
(b) CaSO₄·½H₂O
(c) CaCO₃
(d) CaO
Answer: (b) CaSO₄·½H₂O
18. Washing soda is:
(a) NaHCO₃
(b) Na₂CO₃·10H₂O
(c) NaOH
(d) NaCl
Answer: (b) Na₂CO₃·10H₂O
19. Washing soda is used in:
(a) Cooking
(b) Soap making
(c) Glass industry
(d) Medicines
Answer: (b) Soap making
20. Heating gypsum produces:
(a) Baking soda
(b) Plaster of Paris
(c) Lime
(d) Sodium carbonate
Answer: (b) Plaster of Paris
21. Who discovered the pH scale?
(a) Louis Pasteur
(b) Sørensen
(c) Rutherford
(d) Mendeleev
Answer: (b) Sørensen
22. The pH value of human blood is:
(a) 7.0
(b) 7.4
(c) 6.9
(d) 8.0
Answer: (b) 7.4
23. A pH value between 0 and 7 indicates:
(a) Alkaline
(b) Acidic
(c) Neutral
(d) Salt
Answer: (b) Acidic
24. Which acid is present in a bee sting?
(a) Formic acid
(b) Citric acid
(c) Lactic acid
(d) Acetic acid
Answer: (a) Formic acid
25. The sour taste of lemon is due to:
(a) Citric acid
(b) Lactic acid
(c) Acetic acid
(d) Tartaric acid
Answer: (a) Citric acid
26. Which salt removes the permanent hardness of water?
(a) Na₂CO₃
(b) NaCl
(c) NaHCO₃
(d) NaOH
Answer: (a) Na₂CO₃
27. The main cause of tooth decay is:
(a) Acid
(b) Base
(c) Salt
(d) Sugar
Answer: (a) Acid
28. The common name of sodium hydroxide is:
(a) Baking soda
(b) Caustic soda
(c) Washing soda
(d) Lime
Answer: (b) Caustic soda
29. The pH value of ammonium chloride is:
(a) Less than 7
(b) 7
(c) More than 7
(d) 0
Answer: (a) Less than 7
30. The common name of calcium hydroxide is:
(a) Lime
(b) Slaked lime
(c) Plaster of Paris
(d) Gypsum
Answer: (b) Slaked lime
31. In an acidic solution, the concentration of H⁺ ions is:
(a) Less than OH⁻ ions
(b) More than OH⁻ ions
(c) Equal to OH⁻ ions
(d) Zero
Answer: (b) More than OH⁻ ions
32. The pH value of an alkaline solution is:
(a) Less than 7
(b) 7
(c) More than 7
(d) 0
Answer: (c) More than 7
33. Which of the following is a strong base?
(a) NH₄OH
(b) NaOH
(c) Ca(OH)₂
(d) Mg(OH)₂
Answer: (b) NaOH
34. The reaction between an acid and a metal is called:
(a) Neutralization
(b) Displacement
(c) Oxidation
(d) Combination
Answer: (b) Displacement
35. The color of methyl orange in an acidic solution is:
(a) Yellow
(b) Red
(c) Blue
(d) Colorless
Answer: (b) Red
36. The taste of a base is:
(a) Sour
(b) Bitter
(c) Sweet
(d) Salty
Answer: (b) Bitter
37. The reaction HCl + NaOH → NaCl + H₂O is an example of:
(a) Combination
(b) Neutralization
(c) Displacement
(d) Decomposition
Answer: (b) Neutralization
38. Plaster of Paris, when mixed with water, forms:
(a) Gypsum
(b) Baking soda
(c) Lime
(d) Sodium carbonate
Answer: (a) Gypsum
39. Which of the following is an acidic salt?
(a) NaCl
(b) NaHCO₃
(c) Na₂CO₃
(d) CH₃COONa
Answer: (b) NaHCO₃
40. The color of litmus paper in an alkaline solution is:
(a) Red
(b) Blue
(c) Colorless
(d) Yellow
Answer: (b) Blue
41. Baking soda is used in:
(a) Soap making
(b) Baking food
(c) Glass manufacturing
(d) Metal refining
Answer: (b) Baking food
42. Acid rain is caused by:
(a) CO₂
(b) SO₂ and NO₂
(c) O₂
(d) H₂
Answer: (b) SO₂ and NO₂
43. The pH value of milk is:
(a) 6.5
(b) 7.0
(c) 7.5
(d) 8.0
Answer: (a) 6.5
44. Which of the following is a strong acid?
(a) CH₃COOH
(b) H₂CO₃
(c) HCl
(d) H₂SO₃
Answer: (c) HCl
45. In an alkaline solution, the concentration of H⁺ ions is:
(a) Less than OH⁻ ions
(b) More than OH⁻ ions
(c) Equal to OH⁻ ions
(d) Zero
Answer: (a) Less than OH⁻ ions
46. Which of the following is an amphoteric oxide?
(a) Na₂O
(b) Al₂O₃
(c) CaO
(d) K₂O
Answer: (b) Al₂O₃
47. Antacids contain:
(a) NaOH
(b) Mg(OH)₂
(c) HCl
(d) NaCl
Answer: (b) Mg(OH)₂
48. The color of phenolphthalein in an acidic solution is:
(a) Pink
(b) Colorless
(c) Blue
(d) Yellow
Answer: (b) Colorless
49. Which of the following is not a strong base?
(a) KOH
(b) NaOH
(c) NH₄OH
(d) Ca(OH)₂
Answer: (c) NH₄OH
50. The pH value of water is:
(a) 0
(b) 7
(c) 14
(d) 10
Answer: (b) 7
25 Additional MCQs (From CBSE & MP Board Previous Year Papers)
1. Which compound is used as an antacid? (CBSE 2020)
(a) NaOH
(b) Mg(OH)₂
(c) KOH
(d) Ca(OH)₂
Answer: (b) Mg(OH)₂
2. What is formed when Plaster of Paris is mixed with water? (MP Board 2019)
(a) Gypsum
(b) Baking soda
(c) Lime
(d) Sodium carbonate
Answer: (a) Gypsum
3. Which acid is found in milk? (CBSE 2021)
(a) Citric acid
(b) Lactic acid
(c) Acetic acid
(d) Tartaric acid
Answer: (b) Lactic acid
4. In an alkaline solution, phenolphthalein indicator turns: (MP Board 2020)
(a) Colorless
(b) Pink
(c) Yellow
(d) Blue
Answer: (b) Pink
5. In an acidic solution, methyl orange turns: (CBSE 2019)
(a) Yellow
(b) Red
(c) Blue
(d) Green
Answer: (b) Red
6. The pH value of human blood is: (CBSE 2022)
(a) 7.0
(b) 7.4
(c) 6.9
(d) 8.0
Answer: (b) 7.4
7. What is produced in the reaction between an acid and a base? (MP Board 2021)
(a) Salt + Water
(b) Only salt
(c) Only water
(d) Gas
Answer: (a) Salt + Water
8. Which of the following salts is acidic in nature? (CBSE 2020)
(a) NaCl
(b) Na₂CO₃
(c) NH₄Cl
(d) CH₃COONa
Answer: (c) NH₄Cl
9. On the pH scale, an alkaline solution has a value: (MP Board 2019)
(a) Less than 7
(b) 7
(c) More than 7
(d) 0
Answer: (c) More than 7
10. The pH value of acid rain is: (CBSE 2021)
(a) Less than 5.6
(b) 7
(c) 8
(d) 10
Answer: (a) Less than 5.6
11. The chemical formula of washing soda is: (MP Board 2020)
(a) NaHCO₃
(b) Na₂CO₃·10H₂O
(c) NaOH
(d) NaCl
Answer: (b) Na₂CO₃·10H₂O
12. Baking soda is used for: (CBSE 2019)
(a) Making soap
(b) Softening food
(c) Glass industry
(d) Metal refining
Answer: (b) Softening food
13. Plaster of Paris is used in: (MP Board 2021)
(a) Medicines
(b) Food items
(c) Supporting fractured bones
(d) Clothing
Answer: (c) Supporting fractured bones
14. Used to remove permanent hardness of water: (CBSE 2020)
(a) Baking soda
(b) Washing soda
(c) Caustic soda
(d) Lime
Answer: (b) Washing soda
15. Which of the following is a basic salt? (MP Board 2019)
(a) NaCl
(b) NaHCO₃
(c) CH₃COONa
(d) NH₄Cl
Answer: (c) CH₃COONa
16. Which compound is amphoteric? (CBSE 2021)
(a) NaOH
(b) Al₂O₃
(c) CaO
(d) KOH
Answer: (b) Al₂O₃
17. An aqueous solution of ammonium chloride is: (MP Board 2020)
(a) Acidic
(b) Alkaline
(c) Neutral
(d) None of these
Answer: (a) Acidic
18. Which of the following is a strong acid? (CBSE 2019)
(a) CH₃COOH
(b) HCl
(c) H₂CO₃
(d) H₂SO₃
Answer: (b) HCl
19. The taste of a base is: (MP Board 2021)
(a) Sour
(b) Bitter
(c) Sweet
(d) Salty
Answer: (b) Bitter
20. Which of the following is not a natural indicator? (CBSE 2020)
(a) Turmeric
(b) Litmus
(c) Methyl orange
(d) Hibiscus
Answer: (c) Methyl orange
21. In an acidic solution, blue litmus paper turns: (MP Board 2019)
(a) Red
(b) Blue
(c) Yellow
(d) Green
Answer: (a) Red
22. Which of the following is a weak base? (CBSE 2021)
(a) NaOH
(b) KOH
(c) NH₄OH
(d) Ca(OH)₂
Answer: (c) NH₄OH
23. Which salt is neutral in nature? (MP Board 2020)
(a) NaCl
(b) NH₄Cl
(c) NaHCO₃
(d) CH₃COONa
Answer: (a) NaCl
24. Acid rain is caused by: (CBSE 2019)
(a) CO₂
(b) SO₂ and NO₂
(c) O₂
(d) H₂
Answer: (b) SO₂ and NO₂
25. Which compound is caustic soda? (MP Board 2021)
(a) NaOH
(b) Na₂CO₃
(c) NaHCO₃
(d) NaCl
Answer: (a) NaOH