MCQ | concept of Acids & bases

QUIZ – I

Q:1. Which one of following is the strongest acid

(A) ClO₃^–

(B) ClO₂^–

(C) ClO₄^–

(D) ClO^–

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Ans: (D)

 

Q:2. The conjugate acid of HS₂O₇^– is

(A) H₂S₂O₇

(B) H₂SO₄

(C)HS₂O₆⁺ 

(D) HSO₄^–

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Ans: (A)

 

Q:3. Among the following weakest acid is

(A) HNO₃

(B) H₃AsO₄

(C) H₃SbO₄

(D) H_­3PO₄

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Ans: (C)

 

Q:4. Increasing order of Lewis acid strength

AlCl₃    GaCl₃  InCl₃

I           II          III

(A) I < II < III
(B) III < II < I

(C) II < I < III

(D) III < I < II

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Ans: (B)

 

Q:5. Which one of following is the strongest acid

(A) H₃PO₄

(B) H₃PO₂

(C) H₃PO₃

(D) H₂SO₃

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Ans: (C)

 

Q:6. What is the decreasing order of strength of bases

(A) CH₃ – CH₂^– > NH₂^– > H – C º C^– > OH^–

(B) H – C º C^– > CH₃– CH₂^– > NH₂^– > OH^–

(C) OH^– > NH₂^– > H- C º C^– > CH₃-CH₂^–

(D) NH₂^– > H – C º C^– > OH^– > CH₃ -CH₂^–

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Ans: (A)

 

Q:7. Which of the following is a soft base ?

(A) R₂S

(B) NH₃

(C) H₂O

(D) Cu⁼

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Ans: (A)

 

Q:8. Amongst the following the most basic compound is

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Ans: (A)

 

Q:9. Which of the following is strongest Lewis acid

(A) CH₃^–

(B) F^–

(C) NH₂^–

(D) OH^–

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Ans: (A)

 

Q:10. The conjugate base of H₃O⁺  is

(A) H₂O

(B) OH^–

(C) H⁺

(D) None of these

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Ans: (A)

 

Q:11. The conjugate acid of S₂O₈^–2

(A) H₂S₂O₈

(B) H₂SO₄

(C) HSO₄^–

(D) HS₂O₈^–

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Ans: (D)

 

Q:12. The following acids have been arranged in order of decreasing acid strength. Identify the correct order.

ClOH (I)     BrOH  (II)    IOH (III)

(A) I > II > III

(B) II > I > III

(C) III > II > I

(D) I > III > II

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Ans: (A)

 

Q:13. Which of the following are amphiprotic in nature ?

(A) OH^–

(B) H₂PO₂^–

(C) HSO₃^–

(D) HF

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Ans: (A)

 

Q:14.Among the following compounds, the strongest acid is

(A) HC º CH

(B) C₆H₆

(C) C₂H₆

(D) CH₃OH

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Ans: (A)

 

Q:15. With reference to protonic acid which of the following statement is correct ?

(A) PH₃ is more basic than NH₃

(B) PH₃ is less basic than NH₃

(C)PH₃ is equally basic than NH₃

(D) PH₃ is amphoteric while NH₃ is basic

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Ans: (B)

 

Q:16. Acetic acid is a conjugate base of which acid.

(A) CH₃COO^–

(B) CH₃CH₂COO^–

(C) CH₃COOH₂⁺

(D) None

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Ans: (C)

 

Q:17. Conjugate base of NH₃ is

(A) NH₂^–

(B) NH_­4⁺

(C) NH₄OH

(D) NH₂OH

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Ans: (A)

 

Q:18. Which of the following is the soft base ?

(A) CO₃^2– ion

(B) CO

(C) Ce³⁺

(D) Pb²⁺

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Ans: (B)

 

Q:19. Which among the following is the strongest base

(A) Be(OH)₂

(B) Mg(OH)₂

(C) Ba(OH)₂

(D) Sr(OH)₂

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Ans: (C)

 

Q:20. The conjugate acid of NH₃ is

(A) NH₂^–

(B) NH₂OH

(C) NH₄⁺

(D) N₂H₄

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Ans: (C)

 

Q:21. In the equilibrium CH₃COOH + HF $\rightleftharpoons $ CH₃COOH₂⁺ + F^–

(A) F^– is the conjugate acid of CH₃COOH

(B) F^– is the conjugate base of HF

(C) CH₃COOH is the conjugate acid of

(D)  is the conjugate base of CH₃COOH.

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Ans: (B)

 

Q:22. Which of the following statements is/are correct?

(A) Maleic acid is a stronger acid than fumaric acid but maleate monoanion is a weaker acid than fumarate monoanion

(B) Maleic acid is a stronger acid than fumaric acid and also maleate monoanion is a stronger acid than fumarate monoanion

(C) Maleic acid is a weaker acid than fumaric acid but maleate monoanion is a stronger acid than fumarate monoanion

(D) Maleic acid is a weaker acid than Fumaric acid and also maleate monoanion is a weaker acid than fumarate monoanion.

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Ans: (A)

 

Q:23. Which of the following is the strongest acid

(A) HNO₃

(B) H₂SO₄

(C) HNO₂

(D) All have same strength

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Ans: (B)

 

Q:24. Which of the following species is an acid and also a conjugate base of another acid

(A)  HSO₄^–

(B) H₂SO₄

(C) OH^–

(D) H₃O⁺

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Ans: (A)

 

Q:25. Which of the following orders regarding acid strength is correct ?

(A) HCOOH < CH₃COOH < PhCOOH

(B) HCOOH > PhCOOH > CH₃COOH

(C) HCOOH > CH₃COOH > PhCOOH

(D) CH₃COOH > HCOOH > PhCOOH

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Ans: (B)

 

Q:26. The following equilibrium is established when hydrogen chloride is dissolved in acetic acid.

HCl + CH₃COOH → Cl^– + CH₃COOH₂⁺

The set that characteristics the conjugate acid-base pair is

(A) (HCl, CH₃COOH) and (CH_­3COOH₂⁺ and Cl^–)

(B) (HCl, CH₃COOH₂⁺) and (CH₃COOH, Cl^–)

(C) (CH₃COOH₂⁺, HCl) and  (Cl^–, CH₃COOH)

(D) (HCl, Cl^–) and (CH₃COOH₂⁺, CH₃COOH)

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Ans: (A)

 

Q:27. In the following compounds, the order of acidity is

(A) III > IV > I > II

(B) I > IV > III > II

(C) II > I > III > IV

(D) IV > III > I > II

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Ans: (D)

 

Q:28. Of the following orders regarding basicity, which one is correct

(A) CH₃CH₂NH₂ > PhCONH₂ > CH₃CONH₂

(B) CH₃CH₂NH₂ > PhCONH₂ > CH₃CONH₂

(C) CH₃CH₂NH₂ > PhCONH₂ < CH₃CONH₂

(D) CH₃CH₂NH₂ < PhCONH₂ < CH₃CONH₂

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Ans: (A)

 

Q:29. In the following compounds, the order of basicity

(A) IV > I > III > II

(B) III > I > IV > II

(C) II > I > III > IV

(D) I > III > II > IV

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Ans: (D)

 

Q:30. The conjugate base of $[ Cr(H_2 O)_5 Cl]^{2+} $ is

(A) $[ Cr(H_2 O)_5 ]^{3+} $

(B) $[ Cr(H_2 O)_4 Cl]^{2+} $

(C) $[ Cr(H_2 O)_4 O HCl]^{3+} $

(D) $[ Cr(H_2 O)_4 O HCl]^{+} $

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Ans: (D)

 

Click to See All Answers :

1. (D) 2. (A) 3. (C) 4. (B) 5. (C) 6. (A) 7. (A) 8. (A) 9. (A) 10. (A) 11. (D) 12. (A) 13. (A) 14. (A) 15. (B)
16. (C) 17. (A) 18. (B) 19. (C) 20. (C) 21. (B) 22. (A) 23. (B) 24. (A) 25. (B) 26. (A) 27. (D) 28. (A) 29. (D) 30. (D)