1. What is a base according to Arrhenius theory?
A) Proton donor
B) Electron donor
C) Produces OH⁻ ions in water
D) Produces H⁺ ions in water
Answer: C
2. Which of the following is a strong base?
A) NH₄OH
B) NaOH
C) CH₃COOH
D) HCl
Answer: B
3. Which ion is produced by bases in aqueous solution?
A) H⁺
B) Cl⁻
C) OH⁻
D) Na⁺
Answer: C
4. What is the pH value of a basic solution?
A) Less than 7
B) Equal to 7
C) Greater than 7
D) Equal to 0
Answer: C
5. Which of the following is a weak base?
A) KOH
B) NaOH
C) NH₃
D) Ca(OH)₂
Answer: C
6. Bases turn red litmus paper into:
A) Blue
B) Green
C) Yellow
D) Red
Answer: A
7. Which compound is commonly known as slaked lime?
A) CaO
B) Ca(OH)₂
C) NaOH
D) MgO
Answer: B
8. Which base is used in soap making?
A) HCl
B) NaOH
C) H₂SO₄
D) CH₃COOH
Answer: B
9. What is the chemical name of NH₄OH?
A) Sodium hydroxide
B) Potassium hydroxide
C) Ammonium hydroxide
D) Calcium hydroxide
Answer: C
10. Which of the following bases is insoluble in water?
A) NaOH
B) KOH
C) Al(OH)₃
D) NH₄OH
Answer: C
11. A base reacts with an acid to form:
A) Only water
B) Only salt
C) Salt and water
D) Gas only
Answer: C
12. The reaction between acid and base is called:
A) Oxidation
B) Reduction
C) Neutralization
D) Combustion
Answer: C
13. Which of the following is an alkali?
A) Cu(OH)₂
B) Fe(OH)₃
C) NaOH
D) Zn(OH)₂
Answer: C
14. Which base is used in whitewashing?
A) NaOH
B) Ca(OH)₂
C) NH₃
D) Mg(OH)₂
Answer: B
15. Bases taste:
A) Sour
B) Bitter
C) Sweet
D) Salty
Answer: B
16. Which indicator turns pink in a basic solution?
A) Litmus
B) Methyl orange
C) Phenolphthalein
D) Starch
Answer: C
17. Which of the following is a Brønsted–Lowry base?
A) Proton donor
B) Proton acceptor
C) Electron acceptor
D) Salt
Answer: B
18. Which of the following bases is used as antacid?
A) NaCl
B) Mg(OH)₂
C) HCl
D) HNO₃
Answer: B
19. Which gas forms a basic solution in water?
A) CO₂
B) SO₂
C) NH₃
D) O₂
Answer: C
20. What is the nature of Na₂CO₃ solution?
A) Acidic
B) Neutral
C) Basic
D) Amphoteric
Answer: C
21. Which hydroxide is known as caustic potash?
A) NaOH
B) KOH
C) Ca(OH)₂
D) Mg(OH)₂
Answer: B
22. Which of the following is amphoteric?
A) NaOH
B) KOH
C) Al(OH)₃
D) NH₄OH
Answer: C
23. The strength of a base depends on:
A) Number of H⁺ ions
B) Number of OH⁻ ions produced
C) Color
D) Smell
Answer: B
24. Which of the following is NOT a base?
A) NaOH
B) KOH
C) HCl
D) Ca(OH)₂
Answer: C
25. What happens when a base is dissolved in water?
A) Releases H⁺
B) Releases OH⁻
C) Releases O₂
D) Releases CO₂
Answer: B
26. Which base is used in drain cleaners?
A) NaOH
B) NH₃
C) Mg(OH)₂
D) CaCO₃
Answer: A
27. Which of the following has highest pH?
A) Acid
B) Neutral water
C) Strong base
D) Weak acid
Answer: C
28. A solution with pH 10 is:
A) Acidic
B) Neutral
C) Basic
D) Amphoteric
Answer: C
29. What is the chemical formula of potassium hydroxide?
A) NaOH
B) KOH
C) CaOH
D) KH
Answer: B
30. Bases are also known as:
A) Electrolytes
B) Alkalis (if water soluble)
C) Catalysts
D) Salts
Answer: B
31. A salt is generally formed by the reaction between:
A) Acid and metal
B) Base and metal
C) Acid and base
D) Metal and non-metal
Answer: C
32. What is the chemical formula of common salt?
A) KCl
B) NaCl
C) CaCl₂
D) Na₂SO₄
Answer: B
33. The reaction of an acid with a base to form salt and water is called:
A) Oxidation
B) Combustion
C) Neutralization
D) Reduction
Answer: C
34. Which of the following is an acidic salt?
A) NaCl
B) NH₄Cl
C) K₂SO₄
D) CaCO₃
Answer: B
35. Which salt is formed from a strong acid and strong base?
A) NH₄Cl
B) NaCl
C) Na₂CO₃
D) NH₄NO₃
Answer: B
36. Washing soda is chemically known as:
A) Sodium chloride
B) Sodium bicarbonate
C) Sodium carbonate
D) Calcium carbonate
Answer: C
37. Baking soda has the chemical formula:
A) Na₂CO₃
B) NaHCO₃
C) CaCO₃
D) K₂CO₃
Answer: B
38. Which of the following salts is basic in nature?
A) NH₄Cl
B) NaCl
C) Na₂CO₃
D) HCl
Answer: C
39. Gypsum has the chemical formula:
A) CaSO₄·2H₂O
B) CaCO₃
C) Na₂SO₄
D) MgSO₄
Answer: A
40. Which salt is used in fertilizers?
A) NaCl
B) NH₄NO₃
C) CaCO₃
D) KClO₃
Answer: B