Ethiopia Grade 12 Chemistry Unit 2: Acid-Base Equilibrium Questions Answers. This Practice is the sample multiple-choice question for the Grade 12 Chemistry Entrance examination.
Unit 2: Acid-Base Equilibrium Content
- 1.1 Homogeneous and Heterogeneous Mixtures
- 1.2 Types of Solutions
- 1.3 The Solution Process
- 1.4 Solubility as an Equilibrium Process
- 1.5 Ways of Expressing Concentrations of Solution
- 1.6 Preparation of Solutions
- 1.7 Solution Stoichiometry ..
- 1.8 Describing Reactions in Solution
- 1.9 Colligative Properties of Solutions
Grade 12 Chemistry Unit 2: Acid-Base Equilibrium Test
1. A Brønsted-Lowry base is defined as a substance that:
- acts as a proton donor
- increases [H+] when placed in water
- decreases [H+] when placed in water
- acts as a proton acceptor
2. Given the reaction HC2O4– (aq) + H2O (l) Æ H3O+ (aq) + C2O42– (aq), which of the following is a conjugate acid-base pair?
- HC2O4 – and H2O
- HC2O4 – and H3O+
- HC3O2 – and H3O
- HC3O2 – and H2O
3. In the reaction AlCl3 + Cl–> Æ AlCl4 –, AlCl3 acts as a:
- Salt
- Lewis acid
- Lewis base
- Brønsted base
4. Which of the following is the conjugate base of HCO3–?
- OH –
- CO 3–2
- H 2 CO 3
- HCO 3 +
5. What is the pH of an aqueous solution at 25°C in which [OH–] is 0.00250 M?
- 2.60
- 11.4
- 3.60
- 12.4
6. A substance that is capable of acting as both an acid and a base is:
- amphiprotic
- diprotic
- conjugated
- binary acid-base
7. The magnitude of Kw indicates that:
- water autoionizes very slowly
- water autoionizes very quickly
- water autoionizes only to a very small extent
- water autoionizes completely
8. When sodium acetate is added to an aqueous solution of acetic acid its pH:
- increases
- remains constant
- decreases
- may increase or decrease
9. pKa values of three acids A, B and C, are 4.5, 3.5 and 6.5, respectively. Which of the following represents the correct order of acid strength?
- A > B > C
- C > A > B
- B > A > C
- C > B > A
10. An acid buffer can be prepared by mixing solutions of:
- sodium chloride and hydrochloric acid
- sodium borate and boric acid
- sodium sulfate and sulfuric acid
- sodium hydroxide and hydrochloric acid
11. Which of the following is not true about strong acid-strong base titration?
- the pH is low at the beginning of the titration
- at the equivalence point, the pH is 7.00
- any indicator whose color changes in the pH range from about 4 to 10 can be used
- none of the above
12. Which of the following salts will yield a basic solution on dissolution in water?
- a salt of weak acid and weak base
- a salt of strong acid and strong base
- a salt of weak acid and strong base
- a salt of strong acid and weak base
13. A more generalized acid-base concept is that of:
- Brønsted and Lowry
- Lewis
- Arrhenius
- none of these
14. Which of the following anions is the weakest base?
- NO 2 –
- CH 3 COO –
- NO3 –
- PO 4 3
15. Which of the following buffer solutions has a pH greater than 7?
- CH3COOH/CH3COONa
- HCOOH/HCOOK
- CH3COOH/CH3COONH4
- NH4OH/NH4Cl