CHM 2045C Chapter 5 Kotz5e

Sample Multiple Choice Answers

1. The correct answer is:
c. PbSO₄

Explanation:
Students should know some solubility rules. All ammonium salts and alkali metal salts are soluble.

Solution Reference:
Page 186, Precipitation Reactions

2. The correct answer is:
e. Hg₂Cl₂.

Explanation:
All common chlorides are soluble except AgCl, PbCl₂, and Hg₂Cl₂.

Solution Reference:
Page 186, Precipitation Reactions

3. The correct answer is:
c. (NH₄)₂S.

Explanation:
All ammonium salts are soluble.

Solution Reference:
Page 186, Precipitation Reactions

4. The correct answer is:
c. AgNO₃ and CsBr.

Explanation:
To have success on these questions, a student needs to know the simple solubility rules. Only silver bromide, in response c, is insoluble.

Solution Reference:
Page 186, Precipitation Reactions

5. The correct answer is:
d. the ion, K⁺, could be a spectator ion.

Explanation:
The equation indicates that benzoic acid has been neutralized by a strong base so the base could be NaOH, KOH, or ....

Solution Reference:
Page 189, Net Ionic Equations

6. The correct answer is:
c. H⁺(aq) + OH^-(aq) --> H₂O(l)

Explanation:
Hydrobromic acid is a strong acid and potassium hydroxide is a strong base.

H⁺(aq) + Br^-(aq) + K⁺(aq) + OH^-(aq) --> H₂O(l) + K⁺(aq) + Br^-(aq)

Therefore, K⁺ and Br^- are spectator ions.

Solution Reference:
Page 189, Net Ionic Equations and Page 192, Acids and Bases

7. The correct answer is:
e. H₃PO₄ and HClO.

Explanation:
Both H₃PO₄ and H₃PO₃ are weak acids.

Solution Reference:
Page 192, Acids and Bases

8. The correct answer is:
a. H₂S

Explanation:
Strong acids are strong electrolytes and weak acids are weak electrolytes.

Solution Reference:
Page 192, Acids and Bases

9. The correct answer is:
b. SO₃ and H₂SO₄

Explanation:
SO₃ + H₂O --> H₂SO₄
The oxidation number of the central atom in the acidic oxide has to be the same as that in the acid. Sulfur above has a +6 oxidation state in both SO₃ and H₂SO₄.

Solution Reference:
Page 195, Oxides of Nonmetals and Metals, and Page 206, Oxidation Numbers

10. The correct answer is:
c. will hydrolyze and produce hydroxide ions.

Explanation:
Acidic solutes can react with water (hydrolysis) and produce hydronium ions.

Solution Reference:
Page 192, Acids and Bases

11. The correct answer is:
c. 2H⁺(aq) + 2NaI(s) + H₂SO₄(aq) --> I₂(s) + 2H₂O + SO₂(g) + 2Na⁺

Explanation:
H₂SO₄ has oxidized I^- to I₂ while it has been reduced to SO₂.

Solution Reference:
Page 204, Oxidation-Reduction Reactions

12. The correct answer is:
c. P₄.

Explanation:
Phosphorus is both the oxidizing agent and the reducing agent. Phosphorus has undergone a disproportionation reaction.

Solution Reference:
Page 205, Redox Reactions and Electron Transfer

13. The correct answer is:
d. 3.

Explanation:
Hydrogen bonded to nonmetals has an oxidation number of +1.
3(+1) + y + 3(-2) = 0

Solution Reference:
Page 206, Oxidation Numbers

14. The correct answer is:
c. 3.

Explanation:
NO₂^- ; Y + 2 (-2) = -1

Solution Reference:
Page 206, Oxidation Numbers

15. The correct answer is:
1 only.

Explanation:
Reaction 1 is an oxidation-reduction reaction.
Reaction 2 is an acid-base reaction because there is a proton transfer.
Reaction 3 is a precipitation reaction.

Solution Reference:
Page 201, Organizing Reactions in Aqueous Solution

16. The correct answer is:
b. the number of moles of solute per liter of solution.

Solution Reference:
Page 213, Solution Concentration: Molarity

17. The correct answer is:

b. 5.79

Explanation:

Solution Reference:
Page 213, Solution Concentration: Molarity

18. The correct answer is:
a. 5.61 g

Explanation:


Solution Reference:
Page 213, Solution Concentration: Molarity

19. The correct answer is:
c. 0.006 mol

Explanation:


Solution Reference:
Page 213, Measuring Concentrations

20. The correct answer is:
b. 0.364 L

Explanation:


Solution Reference:
Page 213, Solution Concentration: Molarity

21. The correct answer is:
c. I₂(aq) + H₂O(l) --> HOI(aq) + HI(aq)

Explanation:
Only iodine has a change in oxidation number.

Solution Reference:
Page 201, Organizing Reactions in Aqueous Solution

22. The correct answer is:
e. 200.0 mL

Explanation:


Solution Reference:
Page 222, Titrations

23. The correct answer is:
d. 567

Explanation:


Solution Reference:
Page 222, Titrations

24. The correct answer is:
a. 25.0 ml

Explanation:


Solution Reference:
Page 217, Diluting a More Concentrated Solution

25. The correct answer is:
b. 2.09

Explanation:


Solution Reference:
Page 222, Titrations