1. Which ion is responsible for the acidic nature of a substance?
(A) OH⁻
(B) Cl⁻
(C) H⁺
(D) Na⁺
2. Which of the following is a strong base?
(A) NH₄Cl
(B) CH₃COOH
(C) H₂CO₃
(D) NaOH
3. A substance that turns blue litmus red is generally a:
(A) Acid
(B) Salt
(C) Base
(D) Neutral solution
4. Which gas is released when acids react with metals?
(A) Oxygen
(B) Nitrogen
(C) Carbon dioxide
(D) Hydrogen
5. Which of the following is an example of a weak acid?
(A) HCl
(B) CH₃COOH
(C) HNO₃
(D) H₂SO₄
6. The pH value of a neutral solution is:
(A) 7
(B) 0
(C) 14
(D) 1
7. Which of the following is a natural indicator?
(A) Methyl orange
(B) Litmus
(C) Phenolphthalein
(D) Red oxide
8. Baking soda is chemically:
(A) Sodium carbonate
(B) Magnesium hydroxide
(C) Calcium carbonate
(D) Sodium bicarbonate
9. Which salt is formed from HCl and NaOH?
(A) NaCl
(B) Na₂CO₃
(C) Na₂SO₄
(D) KCl
10. Which of the following has a pH less than 7?
(A) Soap solution
(B) Baking soda
(C) Vinegar
(D) Bleach
11. A base reacts with an acid to form:
(A) Salt + Water
(B) Metal
(C) Hydrogen
(D) Oxides
12. Milk of magnesia is used to treat acidity because it is:
(A) Acidic
(B) Basic
(C) Neutral
(D) A salt
13. Which salt causes hardness in water?
(A) NaCl
(B) KCl
(C) AgCl
(D) CaCO₃
14. Which acid is present in lemon?
(A) Acetic acid
(B) Formic acid
(C) Citric acid
(D) Tartaric acid
15. The process of forming salt by acid–base reaction is called:
(A) Crystallization
(B) Oxidation
(C) Neutralization
(D) Sublimation
16. Which is a characteristic of bases?
(A) Turn red litmus blue
(B) Sour taste
(C) Corrode metals strongly
(D) Release CO₂ with carbonates
17. Common salt is obtained from seawater by:
(A) Evaporation
(B) Filtration
(C) Freezing
(D) Distillation
18. Which acid is present in vinegar?
(A) Acetic acid
(B) Citric acid
(C) Tartaric acid
(D) Sulfuric acid
19. Which of the following is a neutral salt?
(A) NH₄Cl
(B) NaCl
(C) CH₃COONa
(D) Na₂CO₃
20. Which acid is produced in the stomach?
(A) H₂SO₄
(B) HCl
(C) HNO₃
(D) CH₃COOH
21. Which indicator turns pink in basic solutions?
(A) Phenolphthalein
(B) Litmus
(C) Methyl orange
(D) Turmeric
22. Turmeric turns red in:
(A) Acid
(B) Base
(C) Salt
(D) Neutral solution
23. Plaster of Paris is chemically:
(A) Na₂SO₄
(B) CaCO₃
(C) CaSO₄·½H₂O
(D) MgCO₃
24. The pH of a strong base is usually:
(A) Less than 3
(B) Greater than 11
(C) Around 7
(D) Between 4 and 6
25. Which of the following acids is used in car batteries?
(A) Sulfuric acid
(B) Nitric acid
(C) Carbonic acid
(D) Hydrochloric acid
26. Washing soda is chemically:
(A) Na₂CO₃·10H₂O
(B) NaHCO₃
(C) CaCO₃
(D) Mg(OH)₂
27. Which salt is used in making toothpastes?
(A) CaSO₄
(B) CaCO₃
(C) NaCl
(D) K₂SO₄
28. A solution with pH = 2 is:
(A) Neutral
(B) Weakly acidic
(C) Strongly basic
(D) Strongly acidic
29. Lactic acid is found in:
(A) Lemons
(B) Milk
(C) Ant bites
(D) Grapes
30. Tooth decay occurs when pH of the mouth falls below:
(A) 9
(B) 7
(C) 5.5
(D) 11