CH111-131 Midterm 2 Review – Questions and Answers | winter 2026 | 100% Correct - Wilfrid Laurier University.

CH111-131 Midterm 2 Review – Questions and Answers |
winter 2026 | 100% Correct - Wilfrid Laurier University.
Wilfrid Laurier University
2026 Winter CH111 and CH131
Midterm 2 Preparation Worksheet
Instructor: I-San Chan

Please note that this worksheet provides additional practice questions; this worksheet is not a
complete review of the midterm.


Section 1: Multiple Choice Questions
1. Identify the Brønsted–Lowry acid, Brønsted–Lowry base, conjugate acid, and conjugate
base in the following reaction:
2- – –
HPO 4 (aq) + H2O(l) ⇌ H2PO4 (aq) + HO (aq)


Brønsted–Lowry Brønsted–Lowry Conjugate Conjugate
acid base acid base
A. HPO42- H2O H2PO4– HO–
B. HPO42- H2O HO– H2PO4–
C. H2O HPO42- H2PO4– HO–
D. H2O HPO42- HO– H2PO4–


2. Identify the Lewis acid in the following reaction:
A. Co2+
B. NH3
Co2+ (aq) + 6 NH3(aq) ⇌ Co(NH3)62+(aq)
C. H2O
D. Co(NH3)62+


3. A solution has a pH of 7.00 at 50.0 oC. At this temperature, the ion product constant for
water (Kw) is 5.476 × 10–14. Which of the following statements is most accurate?
A. This solution is acidic.
B. This solution is pH neutral.
C. This solution is basic.


4. Which of the following is the closest to the pH of a 0.036 mol/L HNO3 solution at 25 oC?
A. 0.036
B. 1.09
C. 1.44
D. 3.32

, 5. Which of the following is the closest to the pH of a 1.0 × 10-10 mol/L KOH solution at 25 oC?
A. 4.00
B. 7.00
C. 10.00


6. Which of the following solutions would have the highest pH?
A. 0.10 M HClO2, Ka = 1.1 × 10-2
B. 0.10 M HNO2, Ka = 4.6 × 10-4
C. 0.10 M HF, Ka = 3.5 × 10-4
D. 0.10 M HCN, Ka = 4.9 × 10-10


7. Vitamin C (ascorbic acid; pKa = 4.7) is a weak acid. In which of the following will vitamin C
have the lowest percent ionization?
A. Lemon tea, pH = 3.0
B. Mint tea, pH = 6.5
C. Green tea, pH = 8.5
D. The same percent ionization


8. The reaction for the dissociation of pyridine (C5H5N; Kb = 1.9 × 10–9) is:
C5H5N(aq) + H2O(l) ⇌ C5H5NH+(aq) + OH–(aq)
Which of the following is the closest to the pH of a 0.60 M pyridine solution at 25 oC?
A. 4.47
B. 5.06
C. 8.94
D. 9.53


9. Which one of the following salts, when dissolved in water, produces the solution with the
highest pH?
A. LiF
B. AlCl3
C. SrBr2
D. NH4ClO4


10. Which of the following solutions is a buffer system?
A. a solution that is 0.50 M HCN and 0.50 M LiCN
B. a solution that is 0.00050 M HCN and 0.50 M CH3CN
C. a solution that is 0.50 M HBr and 0.50 M Ca(OH)2
D. a solution that is 0.50 M HCl and 0.00050 M NH4Cl