21. Which of the following is an example of a strong base?

• A) NH₃
• B) NaOH
• C) ( H_2O )
• D) HCl
• Answer: B

22. In the reaction ( HCl + H_2O \rightarrow H_3O^+ + Cl^- ), water acts as:

• A) A Bronsted-Lowry base
• B) A Bronsted-Lowry acid
• C) A Lewis acid
• D) A neutral molecule
• Answer: A

23. A buffer solution:

• A) Neutralizes all acids and bases
• B) Resists changes in pH upon the addition of small amounts of acid or base
• C) Changes pH drastically when an acid or base is added
• D) Only works with strong acids
• Answer: B

24. The ionization of acetic acid in water is best represented by:

• A) ( CH_3COOH \rightleftharpoons CH_3COO^- + H^+ )
• B) ( CH_3COOH \rightarrow CH_3COO^- + H_2 )
• C) ( CH_3COOH + OH^- \rightarrow CH_3COO^- + H_2O )
• D) ( CH_3COOH + H_2O \rightarrow H_3O^+ + CH_3COO^- )
• Answer: D

25. Which of the following is an amphoteric substance?

• A) NaOH
• B) HCl
• C) ( H_2O )
• D) KOH
• Answer: C

26. The pH scale ranges from:

• A) 0 to 14
• B) 1 to 7
• C) 0 to 7
• D) 7 to 14
• Answer: A

27. Which of the following is a Lewis acid?

• A) NH₃
• B) H₂O
• C) ( AlCl_3 )
• D) OH⁻
• Answer: C

28. The pOH of a solution is 4. What is the pH?

• A) 4
• B) 10
• C) 7
• D) 14
• Answer: B

29. What is the pH of a 0.01 M HCl solution?

• A) 1
• B) 2
• C) 7
• D) 10
• Answer: B

30. Which theory of acids and bases involves the transfer of protons?

• A) Arrhenius
• B) Bronsted-Lowry
• C) Lewis
• D) None of the above
• Answer: B