WBBSE For Class 9 Physical Science And Environment Acids, Bases And Salts MCQS

Acids, Bases And Salts MCQs

Question 1. An aqueous solution turns blue litmus solution red. Excess addition of which of the following solutions to the above solution reverses the change?
(1) HCl solution
(2) Vinegar solution
(3) H₂SO₄
(4) Caustic soda solution

Answer: (4) Caustic soda solution

Question 2. Which of the following substances changes the colour of pH paper to greenish-blue?
(1) Common salt
(2) Vinegar
(3) An antacid
(4) Orange juice

Answer: (3) An antacid

Question 3. To protect tooth decay you are advised to brush your teeth regularly, the nature of commonly used paste is
(1) Neutral
(2) Acidic
(3) Basic
(4) Corrosive

Answer: (3) Basic

Question 4. If you soak a pH paper into gastric juice, it will indicate a pH 
(1) More than 7
(2) Less than 7
(3) Equal to 7
(4) Less than 1

Answer: (2) Less than 7

Question 5. Which of the following gases is responsible for acid rain?
(1) N₂
(2) CH₄
(3) S₂
(4) H₂

Answer: (3) SO₂

Question 6. Which element is present in all acids?
(1) Hydrogen
(2) Oxygen
(3) Carbon
(4) Nitrogen

Answer: (1) Hydrogen

Question 7. ZnO is
(1) Acidic
(2) Basic
(3) Amphoteric
(4) Neutral oxide

Answer: (3) Amphoteric

Question 8. The weak acid is
(1) HCI
(2) HNO₃
(3) H₂SO₄
(4) H₂CO₃

Answer: (4) H₂CO₃

Question 9. Aqueous solution of P.O is
(1) HPO₃
(2) H₃PO₄
(3) H₃PO₃
(4) H₃PO₂

Answer: (2) H₃PO₄

Question 10. Methyl orange is
(1) Base
(2) Alkali
(3) Indicator
(4) Oxide

Answer: (3) Indicator

Question 11. Minimum quantity of indicator used in neutralisation reaction is
(1) 5 ml
(2) 5.2 ml
(3) 5.5 ml
(4) 2-3 drops

Answer: (4) 2-3 drops

Question 12. The aqueous solutions of bases turn red litmus to
(1) Blue
(2) Colourless
(3) Violet
(4) Yellow

Answer: (1) Blue

Question 13. NaCl is a salt.
(1) Normal
(2) Acid
(3) Basic
(4) Complex

Answer: (1) Normal

Question 14. A strong acid is
(1) H₂SO₄
(2) H₂CO₃
(3) H₃PO₄
(4) CH₃COOH

Answer: (1) H₂SO₄

Question 15. Caustic soda is a base.
(1) Salt
(2) Weak
(3) Strong
(4) Acid

Answer: (3) Strong

Question 16. Sulphuric acid is a/an
(1) Inorganic acid
(2) Organic acid
(3) Weak acid
(1) Hydracid

Answer: (1) Inorganic acid

Question 17. Disolium hydrogen phosphate is a
(1) Normal salt
(2) Basic salt
(3) Acid salt
(4) Double salt

Answer: (3) Acid salt

Question 18. Which of the following compounds is used to prepare vanishing colour ?
(1) NH₄OH
(2) NaOH
(3) Ca(OH)₂
(4) KOH

Answer: (1) NH₄OH

Question 19. Na₂SO₄ is a
(1) Normal salt
(2) Acid salt
(3) Basic salt
(4) Complex salt

Answer: (1) Normal salt

Question 20. Indicator used for neutralisation reaction of H₂SO₄ and NaOH is
(1) Methyl orange
(2) Phenolphthalein
(3) Litmus
(4) Any indicator

Answer: (4) Any indicator

Question 21. The colour of phenolphthalein in dilute sulphuric acid solution is
(1) Red
(2) Yellow
(3) Blue
(4) Colourless

Answer: (4) Colourless

Question 22. The colour of methyl orange in acidic solution is
(1) Red
(2) Yellow
(3) Blue
(4) Orange

Answer: (1) Red

Question 23. Sulphuric acid contains replaceable hydrogen atom/atoms by a metal.
(1) 1
(2) 2
(3) 3
(4) 4

Answer: (2) 2

Question 24. Ammonia is
(1) An acid
(2) A base
(3) A salt
(4) None of thesg

Answer: (2) A base

Question 25. The acidity of CaO is
(1) 1
(2) 2
(3) 3
(4) 4

Answer: (2) 2

Question 26.The basicity of hydrochloric acid is 
(1) 1
(2) 2
(3) 3
(4) 4

Answer: (1) 1

Question 27. Phosphoric acid is a
(1) Monobasic
(2) Dibasic
(3) Tribasic acid
(4) None of these

Answer: (3) Tribasic acid

Question 28. Which one is not an Arrhenius acid?
(1) HCI
(2) HF
(3) HNO₃
(4) C₂H₂

Answer: (4) C₂H₂

Question 29. An acid is a compound
(1) Having hydrogen atom
(2) Having lone pair of electron
(3) That can donate proton
(4) That can accept proton

Answer: (1) Having hydrogen atom

Question 30. A base is that
(1) Has oxygen atom
(2) Can accept proton
(3) Can donate proton
(4) Is sour in taste
Answer: (1) Has oxygen atom

Question 31. Which one is amphoteric?
(1) HCN
(2) NH₃
(3) NaOH
(4) H₂O

Answer: (3) NaOH

Question 32. Which one is a weak acid?
(1) HNO₃
(2) HCI
(3) H₂SO₄
(4) CH₃COOH

Answer: (4) CH₃COOH

Question 33. Baking soda consists of
(1) Na₂CO₃
(2) H₂CO₃
(3) NaHCO₃
(4) CH₃COOH

Answer: (3) NaHCO₃

Question 34. Baking powder is a mixture of NaHCO₃ and
(1) Vinegar
(2) CH₃COOH
(3) Oxalic acid
(4) Tartaric acid

Answer: (4) Tartaric acid

Question 35. Which one is a salt?
(1) HCI
(2) NH₃
(3) NaCl
(4) H₂O

Answer: (3) NaCl

Question 36. Which one is a normal salt?
(1) Na₂SO₄
(2) NaHSO₄
(3) NaHCO₃
(4) Pb(OH)CI

Answer: (1) Na₂SO₄

Question 37. Which one is an acid salt?
(1) NaHSO₄
(2) NaCl
(3) NaSO₄
(4) Cu(OH)NO

Answer: (1) NaHSO₄

Question 38. Which one is a basic salt?
(1) Na₂SO₄
(2) Na₂HPO₄
(3) NaCl
(4) Pb(OH)CI

Answer: (4) Pb(OH)Cl

Question 39. Which one is a double salt?
(1) Ca (OCI)CI (Bleaching powder)
(2) NaKCO₃
(3) [Cu (NH₃)₄]SO₄
(4) FeSO₄.(NH₄)₂SO₄.6H₂O (Mohr’s salt)

Answer: (4) FeSO₄.(NH₄)₂SO₄.6H₂O (Mohrs salt)

40. pH is defined as
(1)  (H₃O⁺)
(2)  log (H₃O⁺)
(3) −log (H₃O⁺)
(4) −(H₃O⁺)

Answer: (3) −log (H₃O⁺)

Question 41. In neutral water at 25°C, [H⁺] in mol/ is
(1) 10⁷
(2) 10.7
(3) 10^-7
(4) 1.0

Ans, (3) 10^-7

Question 42. An acid-base indicator is an organic dye which is chemically
(1) A weak acid
(2) A weak base
(3) Either a weak acid or a weak base
(4) A strong acid or a base

Answer: (3) Either a weak acid or a weak base

Question 43. Acid turns a blue litmus paper to
(1) Red
(2) Deep violet
(3) Green
(4) Colourless

Answer: (1) Red

Question 44.Id and strong base
(2) Weak base-strong acid
(3) Strong acid-strong base
(4) Both strong acid-strong base and weak acid-strong base

Answer: (1) Weak acid and strong base

Question 45. By acid rain, the pH of water body
(1) Is reduced
(2) Is increased
(3) Remains the same
(4) None

Answer: (1) Is reduced