Chapter 4
Reactions in Aqueous Solution
Section A
Question 1
Which of the following compounds is most likely to dissolve in water?
A) BaSO4
B) AgBr
C) CaCO3
D) Na2S
E) None of these compounds would dissolve in water.
Question 2
Which of the following is the correct net ionic equation for the reaction that occurs when solutions of Pb(ClO 3)2 and Na2SO4 are mixed?
A) ClO3-(aq) + Na+(aq) ----> NaClO3(s)
B) Pb2+(aq) + SO42-(aq) ----> PbSO4 (s)
C) Pb(ClO3)2(aq) + Na2SO4(aq) ----> PbSO4(s) + 2 NaClO3(aq)
D) Pb2+(aq) + 2 ClO3-(aq) + 2 Na+(aq) + SO42-(aq) ----> PbSO4(s) + 2 Na+(aq) + 2 ClO3-(aq)
E) None of the above
Question 3
Which of the following is the chemical formula of the salt produced by the neutralization of potassium hydroxide with nitric acid?
A) KOH
B) HNO3
C) H2O
D) KNO3
Question 4
What element is oxidized in the following reaction?
Cd(s) + NiO2(s) + 2 H2O(l) ----> Cd(OH)2(aq) + Ni(OH) 2(aq)
A) Cd
B) H
C) Ni
D) O
E) None of the elements are oxidized. This is not an oxidation-reduction reaction.
Question 5
In the following reaction, which element is the oxidizing agent?
3 Cu(s) + 8 HNO3(aq) ----> 3 Cu(NO3)2(aq) + 2 NO(g) + 4 H2O (l)
A) Cu
B) H
C) O
D) N
E) There is no oxidizing agent. This is not an oxidation-reduction reaction.
Question 6
Which of the following is an example of a metal displacement reaction?
A) 2 P(s) + 3 Cl2(g) ----> 2 PCl3(g)
B) CaBr2(aq) + H2SO4(aq) ----> CaSO4(s) + 2 HBr(aq)
C) 2 Na(s) + 2 H2O(l) ----> 2 NaOH(aq) + H2(g)
D) C3H8(g) + 5 O2(g) ----> 3 CO2(g) + 4 H2O(g)
E) Fe2O3(s) + 2 Al(s) ----> 2 Fe(s) + Al2O3(s)
Question 7
How many grams of lead nitrate, Pb(NO3)2, are needed to make 0.500 L of 0.105 M Pb(NO3)2?
A) 5.25 x 10-2 g
B) 34.8 g
C) 17.4 g
D) 165.6 g
E) None of the above
Question 8
To analyze for barium in an unknown white powder, an excess of sodium sulfate solution was added to a 0.624 g sample of the powder dissolved in
water. A white precipitate of BaSO4 was isolated, dried, and found to weigh 0.438 g. What is the mass percent of Ba in the white powder?
A) 0.267%
B) 41.3%
C) 58.9%
D) 70.2%
E) None of the above
Question 9
The acidic substance in vinegar is acetic acid, HC2H3O2. When 4.00 g of a certain vinegar sample was titrated with 0.200 M NaOH, 25.56 mL of the
NaOH solution were required to reach the equivalence point. What is the percent composition by mass of HC 2H3O2 in the vinegar?
A) 7.68%
B) 30.7%
C) 76.8%
D) 3.84%
E) None of the above
Question 10
The mass percent of iron in an iron ore can be determined by converting Fe to Fe2+ in acid solution, and then titrating the dissolved sample with
KMnO4 solution. A 2.51 g ore sample dissolved in acid required 28.62 mL of 0.0821 M KMnO 4 to reach the equivalence point. Calculate the mass
percent of iron in the ore.
8 H+(aq) + 5 Fe2+(aq) + MnO4-(aq) ----> 5 Fe3+ (aq) + Mn2+(aq) + 4 H2O(l)
A) 1.05%
B) 3.82%
C) 5.23%
D) 26.1%
E) None of the above
Question 11
A solution able to conduct electricity contains a dissolved substance called a/an:
A) precipitate
B) electrolyte
C) nonelectrolyte
D) equilibrium
Question 12
Which of the following are examples of soluble compounds?
A) Hydroxides
B) Chromates
C) Sulfides
D) Nitrates
Question 13
Which of the following is incorrectly paired?
A) Ba(OH)2; weak electrolyte
B) NaOH; strong electrolyte
C) H3PO4; triprotic acid
D) H2SO4; diprotic acid
Question 14
Which statement is false concerning oxidation numbers?
A) An element's oxidation number is constant and unchanging.
B) Atoms of free elements have an oxidation number of zero.
C) An atom's oxidation state signifies the number of charges for that atom in a molecule.
D) Oxidation numbers allow easy identification of which atoms gained or lost electrons.
SectionB
Question 1
Which of the following compounds should be insoluble in water?
A) AgNO3
B) Na2CO3
C) PbCl2
D) Na2S
E) NH4Cl
Question 2
The correct complete ionic equation for the reaction that occurs when aqueous solutions of Ca(NO 3)2 and Na2CO3 are mixed is
A) Ca(NO3)2(aq) + Na2CO3(aq) → CaCO3(s) + 2 NaNO3(aq)
B) Ca2+(aq) + 2 NO3-(aq) + 2 Na+(aq) + CO32-(aq) → CaCO3(s) + 2 Na+(aq) + 2 NO3-(aq)
C) Ca2+(aq) + 2 NO3-(aq) + 2 Na+(aq) + CO32-(aq) → Ca2+(aq) + CO32-(aq) + 2 NaNO3(s)
D) Ca2+(aq) + CO32-(aq) → CaCO3(s)
E) Na+(aq) + NO3-(aq) ----> NaNO3(s)
Question 3
Which of the following is a neutralization reaction?
A) HCl(aq) + AgNO3(aq) ----> AgCl(s) + HNO3 (aq)
B) CuSO4(aq) + Zn(s) ----> ZnSO4(aq) + Cu(s)
C) 2 K(s) + 2 H2O(l) ----> 2 KOH(aq) + H2(g)
D) H2SO4(aq) + 2 NaOH(aq) ----> 2 H2O(l) + Na2SO4(aq)
E) None of the above.
Question 4
What is the oxidation number of Cr in K2Cr2O7?
A) +12
B) +3
C) +4
D) +5
E) +6
Question 5
In which of the following reactions does an oxidation-reduction process occur?
A) HCl(aq) + AgNO3(aq) ----> AgCl(s) + HNO3 (aq)
B) CuSO4(aq) + Zn(s) ----> ZnSO4(aq) + Cu(s)
C) 2 K(s) + 2 H2O(l) ----> 2 KOH(aq) + H2(g)
D) 2 HCl(aq) + Ca(OH) 2(aq) ----> 2 H2O(l) + CaCl2(aq)
E) B and C
Question 6
What volume of 3.0 M NaOH can be prepared using exactly 96.0 g of NaOH?
A) 0.14 L
B) 0.70 L
C) 0.80 L
D) 1.25 L
E) 7.20 L
Question 7
What volume of water must be added to 300 mL of 0.75 M HCl to dilute the solution to 0.25 M?
A) 900 mL
B) 600 mL
C) 300 mL
D) 930 mL
E) 100 mL
Question 8
A 1.25-g sample of ore containing iron pyrite (FeS2) was pulverized and ignited in air, converting the FeS2 to Fe2O3 and SO 2(g). The
Fe2O3produced weighed 0.516 g. What was the percent Fe in the ore?
A) 28.9%
B) 36.1%
C) 14.4%
D) 41.3%
E) None of the above.
Question 9
Muriatic acid is a HCl solution available in hardware stores. A 3.00-mL sample of muriatic acid required 15.44 mL of 2.04 M NaOH for complete
neutralization. What is the molarity of HCl in the muriatic acid sample?
A) 0.0952 M
B) 0.396 M
C) 0.0227 M
D) 10.5 M
E) None of the above.
Question 10
The concentration of hydrogen peroxide (H2O2) in an H2O2 solution can be determined if the solution is acidified and titrated with potassium
permanganate, according to the chemical reaction below. What is the molarity of a H 2O2 solution if 20.00 mL of the solution requires 28.16 mL of
0.500 M KMnO4 for complete titration?
2 MnO4-(aq) + 5 H2O2(aq) + 6 H+(aq) ----> 5 O2(g) + 2 Mn2+(aq) + 8 H2O(l)
A) 0.0352 M
B) 0.0250 M
C) 1.76 M
D) 0.282 M