WCB Quiz: H - Precipitation Reactions

ANSWERS SHOWN IN BOLD.

1. What statment below concerning the following reaction from Lab 3 is correct?

a. Cu⁺ is a spectator ion

b. Na⁺ appears in the net ionic equation

c. OH^- does not appear in the net ionic equation

d. NO₃ is a spectator ion

2. If Pb(NO₃)₂(aq) is mixed with LiBr(aq), which is most likely to happen?

a. PbBr₂ will precipitate

b. LiNO₃ will precipitate

c. Both PbBr₂ and LiNO₃ will precipitate

d. Neither PbBr₂ and LiNO₃ will precipitate

3. If (NH₄)₂SO₄ (aq) is mixed with CaBr₂(aq), which is most likely to happen?

a. NH₄Br precipitates

b. CaSO₄ precipitates

c. Both NH₄Br and CaSO₄ precipitate

d. Neither NH₄Br or CaSO₄ precipitates

4. Which statement concerning solubility is generally true?

a. All nitrates are soluble

b. Most sulfates are soluble

c. Most hydroxides are slightly soluble or insoluble

d. All of the above are generally true

5. In writing the total ionic equation for the reaction (if any) that occurs when solutions of KOH and Mg(NO3)2 are mixed, which of the following would NOT be written as ionic species.

a. KOH

b. Mg(NO3)2

c. Mg(OH)2

d. KNO3

e. All of the above

6. Iron (II) sulfate (II implies a charge of 2+ on the Fe) reacts with potassium hydroxide in aqueous solution to form a precipitate. The net ionic equation for this reaction is

a. Fe2+ + (SO4)2- gives FeSO4

b. 2K+ + (SO4)2- gives K2SO4

c. 2Fe3+ + 3(SO4)2- gives Fe2(SO4)3

d. Fe2+ + 2OH- give Fe(OH)2

e. K+ + Fe2+ gives Fe3+

7. Aqueous solutions of sodium chloride and copper (II) bromide are mixed together. Which statement is correct?

a. Both NaBr and CuCl₂ precipitate from solution.

b. No precipitate forms.

c. CuCl₂ will precipitate from solution.

d. NaBr will precipitate from solution.

8. Which of the following salts is insoluble in water?

a. Na2S

b. K3PO4

c. Pb(NO3)2

d. CaCl2

e. All of these are soluble in water.

WCB Quiz I - Redox Reactions

ANSWERS SHOWN IN BOLD.

1. What statment below concerning the following reaction is correct?

a. Zn is oxidized and HCl reduced

b. Zn is reduced and HCl oxidized

c. Zn is an oxidizing agent

d. HCl is reducing agent

2. CH₄ can be converted to CCl₄. What are the oxidation numbers of the C in CH₄ and CCl₄, respectively ?

a. 0, 0

b. 4+, 4-

c. 4-, 4+

d. 0, 4-

3.What is the oxidation number for P in phosphoric acid, H₃PO₄.

a. 0

b. 3+

c. 5+

d. 5-

4. What is the oxidation number for Mn in KMnO₄?

a. 0

b. 3+

c. 5+

d. 7+

WCB Quiz J - Acid/Base Reactions

ANSWERS SHOWN IN BOLD.

1. Which statement about acids is true?

a. Acids form H⁺ ions in solution

b. Strong acids are not electrolytes

c. Acids are proton acceptors

d. When acids interact with water, one of the products derived from the acid is a base

2. What statment below concerning the following reaction is correct?

a. HNO₃(aq) is a stronger acid than H₃O⁺(aq)

b. HNO₃(aq) is a weaker acid than H₃O⁺(aq)

c. H₂O(l) is a weaker base than NO₃^-(aq)

d. H₂O(l) is the solvent, not a base.

3. What statment below concerning the following reaction is correct?

a. After the reaction is complete, there is essential no HCl(aq) remaining in solution.

b. HCl(aq) is a weaker acid than H₃O⁺(aq)

c. Cl^-(aq) is a stronger base than H₂O(l) (aq)

d. Very little of the HCl dissociates into ions.

4. . What statment below concerning the following reaction is correct?

Fe(NO₃)₃(aq) + 3NaOH(aq) --> Fe(OH)₃(s) + 3NaNO₃(aq)

a. NaOH acts as a base

b. NaOH acts as a oxidizing ageent

c. NaOH acts as a precipitating agent

d. NaOH acts as a reducing agent.

WCB Quiz K - Copper Reactions

ANSWERS SHOWN IN BOLD.

1. Reaction 1 is a(n)

a. acid/base rx.

b. redox rx.

c. precipitation rx

d. none of the above

2.In reaction 2, NaOH acts as a(n)

a. base

b. oxidizing agent

c. reducing agent

d. precipitating agent

3. In reaction 2, the oxidation numbers of N in the reactant Cu(NO₃)₂(aq) and in the product NO₂ are, respectively:

a. +5, +5

b.+4, +4

c.+5, +4

d. none of the above

4. In reaction 4, H₂SO₄ acts

a. to dissolve CuO and then as an oxidizing agent

b. to dissolve CuO and then as an acid

c. to dissolve CuO and then as a reducing agent

d. to dissolve CuO and then as a base

5. In reaction 6, Zn(s) acts as a(n)

a. reducing agent

b. oxidizing agent

c. precipitating agent

d. it plays no role in the reaction