Oxidation-Reduction Reactions Complete Test Bank Ch.5

Chemistry: Molecular Nature of Matter, 8e (Jespersen)

Chapter 5 Oxidation-Reduction Reactions

1) Oxidation is defined as

A) gain of a proton.

B) loss of a proton.

C) gain of an electron.

D) loss of an electron.

E) capture of an electron by a neutron.

Diff: 1

Section: 5.1

2) Reduction is defined as

A) gain of a proton.

B) loss of an electron.

C) gain of an electron.

D) gain of a neutron.

E) loss of a proton.

Diff: 1

Section: 5.1

3) What is the oxidation number of sulfur in the S2O82 ion?

A) -2

B) +1

C) +3

D) +5

E) +7

Diff: 1

Section: 5.1

4) What is the oxidation number of chlorine in HClO4?

A) -1

B) +3

C) +5

D) +7

E) +9

Diff: 1

Section: 5.1

5) What is the oxidation number of sodium in Na2O2?

A) -2

B) -1

C) +1

D) +2

E) +4

Diff: 2

Section: 5.1

6) What is the oxidation number of boron in Na2B4O7?

A) -3

B) +1

C) +5

D) +3

E) +6

Diff: 1

Section: 5.1

7) What is the oxidation number of cobalt in Co2(SO4)3?

A) +3

B) +6

C) +9

D) +15

E) +30

Diff: 1

Section: 5.1

8) What is the oxidation number of sulfur in Rb2S2O4?

A) -2

B) +1

C) +3

D) +5

E) +6

Diff: 1

Section: 5.1

9) What is the oxidation number of oxygen in BaO2?

A) -1

B) -2

C) +1

D) +2

E) +3

Diff: 1

Section: 5.1

10) What is the oxidation number of carbon in K2C2O4?

A) 0

B) -4

C) +3

D) +4

E) +6

Diff: 1

Section: 5.1

11) What is the oxidation number of vanadium in (NH4)3VO4?

A) +2

B) +3

C) +5

D) +6

E) +7

Diff: 1

Section: 5.1

12) What is the oxidation number of nitrogen in (NH4)2SO4?

A) -3

B) -2

C) +1

D) +2

E) +3

Diff: 1

Section: 5.1

13) What is the oxidation number of oxygen in H2O2?

A) 0

B) -1

C) +1

D) +2

E) -2

Diff: 2

Section: 5.1

14) What is the oxidation number of each Cu atom in [Cu2Cl6]2-?

A) +5

B) +4

C) +3

D) +2

E) +1

Diff: 2

Section: 5.1

15) What is the oxidation number of the arsenic atom in the AsO43 ion?

A) +1

B) +3

C) +4

D) +5

E) +6

Diff: 2

Section: 5.1

16) Which statement is true concerning an oxidation-reduction reaction?

A) The reactant which is reduced is the reducing agent.

B) The reactant which is oxidized is the reducing agent.

C) The reactant which gains electrons is the reducing agent.

D) The reactant which loses electrons is the oxidizing agent.

E) None of the statements, A–D, is true.

Diff: 2

Section: 5.1

17) Which statement is true concerning an oxidation-reduction reaction?

A) The reactant which is reduced is the oxidizing agent.

B) The reactant which is oxidized is the oxidizing reagent.

C) The reactant which gains electrons is the reducing agent.

D) The reactant which loses electrons is the oxidizing agent.

E) None of the statements, A–D, is true.

Diff: 1

Section: 5.1

18) In a chemical reaction, one of the reactants is MnO2. It is transformed into MnSO4. What is the change in the oxidation number of the manganese?

A) There is no change in oxidation number.

B) The oxidation number increases by one unit.

C) The oxidation number increases by two units.

D) The oxidation number decreases by one unit.

E) The oxidation number decreases by two units.

Diff: 2

Section: 5.1

19) The CrO42- ion was involved in a chemical reaction, during which it is transformed into Cr3+ ions. What is the change in oxidation number of the chromium atom?

A) The oxidation number increases by 5 units.

B) The oxidation number decreases by 5 units.

C) The oxidation number increases by 1 unit.

D) The oxidation number decreases by 3 units.

E) The oxidation number decrease by 4 units.

Diff: 2

Section: 5.1

20) Which of the following involves oxidation?

A) Ba2+(aq) + CrO42-(aq) → BaCrO4(s)

B) 2 H+(aq) + CO32-(aq) → H2O(l) + CO2(g)

C) Fe3+(aq) → Fe2+(aq)

D) MnO2(s) → MnO4-(aq)

E) 2 CrO42-(aq) + 2 H+(aq) → Cr2O72-(aq) + H2O(l)

Diff: 2

Section: 5.1

21) Which of the following involves reduction?

A) Ba2+(aq) + CrO42-(aq) → BaCrO4(s)

B) 2 H+(aq) + CO32-(aq) → H2O(l) + CO2(g)

C) CrO42-(aq) → Cr3+(aq)

D) MnO2(s) → MnO4-(aq)

E) 2 CrO42-(aq) + 2 H+(aq) → Cr2O72-(aq) + H2O(l)

Diff: 2

Section: 5.1

22) Which of the following involves oxidation?

A) Ca2+(aq) + CO32-(aq) → CaCO3(s)

B) 2 H+(aq) + SO32-(aq) → H2O(l) + SO2(g)

C) VO43-(aq) → VO2+(aq)

D) CrO2- (aq) → CrO42-(aq)

E) 2 S2O72-(aq) + H2O(l) → 2 SO42-(aq) + 2 H+(aq)

Diff: 2

Section: 5.1

23) Which of the following involves reduction?

A) Ca2+(aq) + CO32-(aq) → CaCO3(s)

B) 2 H+(aq) + SO32-(aq) → H2O(l) + SO2(g)

C) VO43-(aq) → VO2+(aq)

D) CrO2- (aq) → CrO42-(aq)

E) 2 S2O72-(aq) + H2O(l) → 2 SO42-(aq) + 2 H+(aq)

Diff: 2

Section: 5.1

24) What is the change in the oxidation number of chromium in the following?

K2Cr2O7 s Cr2(SO4)3

A) increase by three units

B) increase by four units

C) decrease by two units

D) decrease by three units

E) decrease by four units

Diff: 2

Section: 5.1

25) What is the change in the oxidation number of carbon in the following?

CO → CO2

A) increase by two units

B) increase by three units

C) increase by four units

D) decrease by three units

E) decrease by four units

Diff: 2

Section: 5.1

26) What is the change in the oxidation number of nitrogen in the following?

HNO3 → NO

A) increase by three units

B) increase by four units

C) decrease by two units

D) decrease by three units

E) decrease by four units

Diff: 2

Section: 5.1

27) What is the change in the oxidation number of manganese in the following?

KMnO4 → MnSO4

A) increase by two units

B) increase by three units

C) decrease by four units

D) decrease by five units

E) decrease by six units

Diff: 2

Section: 5.1

28) What is the change in the oxidation number of sulfur in the following?

K2SO3 → K2SO4

A) decrease by three units

B) decrease by four units

C) increase by two units

D) increase by three units

E) increase by four units

Diff: 2

Section: 5.1

29) What is the change in the oxidation number of iodine in the following?

KI → KIO3

A) decrease by three units

B) decrease by four units

C) increase by six units

D) increase by five units

E) increase by four units

Diff: 2

Section: 5.1

30) What is the change in the oxidation number of carbon in the following?

K2C2O4 → K2CO3

A) decrease by one unit

B) decrease by two units

C) decrease by three units

D) increase by one unit

E) increase by two units

Diff: 2

Section: 5.1

31) In the equation, C4H10(l) + Cr2O72-(aq) + H+(aq) → H6C4O4(s) + Cr3+(aq) + H2O(l), the change in the oxidation number of the chromium atom is

A) a decrease by six units.

B) a decrease by three units.

C) an increase by three units.

D) an increase by five units.

E) an increase by eight units.

Diff: 2

Section: 5.1

32) In the equation, CrO42-(aq) + H2O(l) → CrO2-(aq) + OH-(aq), the change in the oxidation number of the chromium atom is

A) decrease by six units.

B) decrease by three units.

C) increase by three units.

D) increase by five units.

E) increase by eight units.

Diff: 2

Section: 5.1

33) The sulfite ion (SO32-) was involved in a chemical reaction in which it underwent oxidation. Based on the change in oxidation numbers, which of the species listed below is a possible oxidation product of the reaction?

A) S2O3 2-(aq)

B) SO2(g)

C) S2-(aq)

D) S(s)

E) SO42-(aq)

Diff: 2

Section: 5.1

34) The nitrogen molecule, (N2), was involved in a chemical reaction in which it underwent reduction. Based on the change in oxidation numbers, which of the species listed below is a possible product of the reaction?

A) N2H4

B) NO

C) NO2-

D) NO2

E) NO3-

Diff: 2

Section: 5.1

35) The ClO2 molecule was involved in a chemical reaction in which it underwent oxidation. Based on the change in oxidation numbers, which of the species listed below is a possible product of the reaction?

A) ClO-

B) Cl-

C) ClO2-

D) Cl2

E) ClO3-

Diff: 2

Section: 5.1

36) The NO molecule underwent oxidation during a chemical reaction. Which one of the species listed below is a possible product of the reaction?

A) N2H4

B) NH3

C) N2

D) NO2-

E) NH2OH

Diff: 2

Section: 5.1

37) The following unbalanced equation describes the production of metallic iron:

Fe2O3 + C → Fe + CO2

What is the change in oxidation number for the carbon atom?

A) decreases by 1

B) increases by 2

C) increases by 3

D) increases by 4

E) decreases by 5

Diff: 2

Section: 5.1

38) Given the following chemical equation:

SiO2 + CaCO3 → CaSiO3 + CO2

What is the change in oxidation number for silicon atom?

A) There is no change.

B) decreases by 1

C) increases by 2

D) decreases by 3

E) increases by 4

Diff: 2

Section: 5.1

39) Consider the redox equation below:

C4H10(g) + Cr2O72(aq) + H+(aq) → H6C4O4(aq) + Cr3+(aq) + H2O(l)

The reducing agent is

A) C4H10(g)

B) Cr2O72(aq)

C) H+(aq)

D) H6C4O4(aq)

E) Cr3+(aq)

Diff: 2

Section: 5.1

40) Consider the unbalanced redox equation,

C4H10(l) + Cr2O72-(aq) + H+(aq) → H6C4O4(s) + Cr3+(aq) + H2O(l)

The oxidizing agent is

A) C4H10(l)

B) Cr2O72-(aq)

C) H+(aq)

D) H6C4O4(s)

E) Cr3+(aq)

Diff: 2

Section: 5.1

41) Consider the unbalanced redox equation,

VO43-(aq) + SO2(g) + 2 H+(aq) → VO2+(aq) + SO42-(aq) + H2O(l)

The reducing agent is

A) VO43-(aq).

B) VO2+(aq).

C) H+(aq).

D) SO2(g).

E) SO42-(aq).

Diff: 2

Section: 5.1

42) Consider the redox equation,

2VO43-(aq) + SO2(g) + 8H+(aq) → 2VO2+(aq) + SO42-(aq) + 4H2O(l)

The oxidizing agent is

A) VO43-(aq)

B) VO2+(aq)

C) H+(aq)

D) SO2(g)

E) SO42-(aq)

Diff: 2

Section: 5.1

43) Consider the redox equation,

2VO43-(aq) + SO2(g) + 8H+(aq) → 2VO2+(aq) + SO42-(aq) + 4H2O(l)

Which of the following is correct?

Hint: Write out the oxidation numbers for each element in the equation then compare.

A) VO43-(aq) is the oxidizing agent as the oxidation number of O decreases by 3.

B) VO2+(aq) is the reducing agent as the oxidation number of V increases by 1, causing the oxidation number of S to increase by 1 also.

C) H+(aq) is the reducing agent, its oxidation number increases from 1 to 2, as it must have lost one electron.

D) VO43-(aq) is the oxidizing agent, as the oxidation number of V decreases by 1, suggesting it must have accepted an electron.

E) SO42-(aq) is the oxidizing agent and the product formed from the reduction of SO2(g).

Diff: 3

Section: 5.1

44) The following unbalanced equation describes the production of metallic iron:

Fe2O3 + C → Fe + CO2

Which is true?

Hint: Remember the reducing agent is oxidized and the oxidizing agent is reduced.

A) Fe2O3 is the reducing agent, since it is reduced, while C is the oxidizing agent, since it

oxidizes Fe2O3.

B) Fe2O3 is the reducing agent, while Fe is the oxidizing agent, as it oxidizes C to CO2.

C) Fe is the reducing agent, since it reduces C, while C is the oxidizing agent.

D) Fe2O3 is the oxidizing agent, while C is the reducing agent, since it reduces Fe2O3.

E) Fe2O3 is the reducing agent, while CO2 is the oxidizing agent.

Diff: 3

Section: 5.1

45) Balance the half-reaction, H2S → S8, taking place in acidic media. How many electrons are needed to balance the half-reaction?

Hint: Remember the coefficients when balancing half-reactions, and look carefully at the oxidation numbers.

A) 12 electrons, left side

B) 16 electrons, right side

C) 14 electrons, left side

D) 6 electrons, right side

E) 8 electrons, right side

Diff: 3

Section: 5.2

46) Balance the half-reaction, NO3 → NH4+, taking place in acidic media. How many electrons are needed to balance the half-reaction?

Hint: Remember the coefficients when balancing half-reactions and look carefully at the oxidation numbers.

A) 2 electrons, left side

B) 3 electrons, right side

C) 4 electrons, left side

D) 8 electrons, left side

E) 8 electrons, right side

Diff: 3

Section: 5.2

47) Balance the half-reaction, Cl2O7 → HClO, taking place in acidic media. How many electrons are needed to balance the half-reaction?

Hint: Remember the coefficients when balancing half-reactions and look carefully at the oxidation numbers.

A) 2 electrons, left side

B) 3 electrons, right side

C) 12 electrons, left side

D) 6 electrons, right side

E) 8 electrons, left side

Diff: 3

Section: 5.2

48) Balance the half-reaction, C2H6O → HC2H3O2, taking place in acidic media. How many electrons are needed to balance the charge?

Hint: Remember the coefficients when balancing half-reactions and look carefully at the oxidation numbers.

A) 2 electrons, left side

B) 3 electrons, left side

C) 4 electrons, right side

D) 6 electrons, right side

E) 8 electrons, right side

Diff: 3

Section: 5.2

49) Balance the half-reaction, C8H10 → C8H4O42, taking place in basic media. How many electrons are needed to balance the half-reaction?

Hint: Remember the coefficients when balancing half-reactions and look carefully at the oxidation numbers.

A) 4 electrons, left side

B) 8 electrons, right side

C) 8 electrons, left side

D) 12 electrons, left side

E) 12 electrons, right side

Diff: 3

Section: 5.2

50) Complete the balancing of the following half-reaction, taking place in basic media. How many electrons are needed to balance the half-reaction?

Br(aq) → BrO3(aq)

Hint: Remember the coefficients when balancing half-reactions and look carefully at the oxidation numbers.

A) 2 electrons, left side

B) 2 electrons, right side

C) 4 electrons, right side

D) 6 electrons, right side

E) 6 electrons, left side

Diff: 3

Section: 5.2

51) Complete the balancing of the following half-reaction, taking place in basic media. How many electrons are needed to balance the half-reaction?

Cr(OH)4(aq) → CrO42(aq)

Hint: Remember the coefficients when balancing half-reactions and look carefully at the oxidation numbers.

A) 1 electron, on the left side

B) 2 electrons, on the right side

C) 3 electrons, on the right side

D) 3 electrons, on the left side

E) 4 electrons, on the right side

Diff: 3

Section: 5.2

52) Complete the balancing of the following half-reaction, taking place in basic media. How many hydroxide ions are needed to balance the half-reaction?

Br(aq) s BrO3(aq)

Hint: Remember the coefficients when balancing half-reactions and look carefully at the oxidation numbers.

A) 2 hydroxide ions, on the left side

B) 4 hydroxide ions, on the left side

C) 4 hydroxide ions, on the right side

D) 6 hydroxide ions, on the left side

E) 6 hydroxide ions, on the right side

Diff: 3

Section: 5.2

53) Complete the balancing of the following half-reaction, taking place in basic media. How many hydroxide ions are needed to balance the half-reaction?

Cr(OH)4(aq) → CrO42(aq)

Hint: Remember the coefficients when balancing half-reactions and look carefully at the oxidation numbers.

A) 1 hydroxide ion, on the left side

B) 3 hydroxide ions, on the right side

C) 3 hydroxide ions, on the left side

D) 4 hydroxide ions, on the left side

E) 4 hydroxide ions, on the right side

Diff: 3

Section: 5.2

54) After balancing the following equation for the reaction in acidic media,

Fe2+(aq) + Cr2O72(aq) + H+(aq) → Cr3+(aq) + Fe3+(aq) + H2O(l)

what is the sum of ALL the coefficients in the equation?(Remember to include values of 1 in your summation.)

Hint: Start by balancing each half-reaction.

A) 6

B) 22

C) 30

D) 32

E) 36

Diff: 3

Section: 5.2

55) After balancing the following equation for the reaction in acidic media,

MnO4-(aq) + H2C2O4(aq) + H+(aq) → Mn2+(aq) + CO2(g) + H2O(l)

what is the sum of ALL the coefficients in the equation?(Remember to include values of 1 in your summation.)

Hint: Start by balancing each half-reaction.

A) 29

B) 30

C) 31

D) 32

E) 33

Diff: 3

Section: 5.2

56) After balancing the following equation for the reaction in acidic media,

H+ + HSO3-(aq) + MnO4-(aq) → MnO2(s) + HSO4-(aq) + H2O

what is the sum of ALL the coefficients in the equation? (Remember to include values of 1 in your summation.)

Hint: Start by balancing each half-reaction.

A) 7

B) 9

C) 13

D) 15

E) 19

Diff: 3

Section: 5.2

57) After balancing the following equation for the reaction in basic media,

OH- + Bi2O3(s) + OCl-(aq) → Cl-(aq) + BiO3-(aq) + H2O

what is the sum of ALL the coefficients in the equation? (Remember to include values of 1 in your summation.)

Hint: Start by balancing each half-reaction.

A) 6

B) 8

C) 9

D) 10

E) 14

Diff: 3

Section: 5.2

58) After balancing the following equation for the reaction in basic media,

H2O + CrO42-(aq) + Br-(aq) → CrO2-(aq) + BrO3-(aq) + OH-

what is the sum of ALL the coefficients in the equation? (Remember to include values of 1 in your summation.)

Hint: Start by balancing each half-reaction.

A) 6

B) 8

C) 9

D) 10

E) 14

Diff: 3

Section: 5.2

59) After balancing the following equation for the reaction in basic media,

I-(aq) + MnO4-(aq) → I2(aq) + MnO2(s)

what is the sum of ALL the coefficients in the equation? (Remember to include values of 1 in your summation.)

Hint: Start by balancing each half-reaction.

A) 6

B) 13

C) 17

D) 25

E) 28

Diff: 3

Section: 5.2

60) Zinc metal reacts with perchloric acid solution to produce aqueous zinc perchlorate and hydrogen gas, which escapes. The species being oxidized in this reaction is

A) HClO4(aq).

B) H2(g).

C) Zn2+(aq).

D) Zn(s).

E) Zn(ClO4)2(aq).

Diff: 2

Section: 5.3

61) Sodium bicarbonate, (NaHCO3), in solution reacts with hydrochloric acid solution to produce aqueous sodium chloride, carbon dioxide gas, and water. The species being reduced in this reaction is

Hint: Oxidation is a loss of electrons and reduction is a gain of electrons.

A) HCO3- (aq).

B) CO2(g).

C) HCl(aq).

D) Cl-(aq).

E) none of the above.

Diff: 3

Section: 5.3

62) Zinc metal reacts with nitric acid solution to produce aqueous zinc nitrate, ammonium nitrate (in solution), and water. The species being oxidized in this reaction is

A) HNO3(aq).

B) NH4+(aq).

C) Zn2+(aq).

D) Zn(s).

E) Zn(NO3)2(aq).

Diff: 2

Section: 5.3

63) Zinc metal reacts with nitric acid solution to produce zinc nitrate (in solution), ammonium nitrate (in solution), and water. The species being reduced in this reaction is

A) HNO3(aq).

B) NH4+(aq).

C) Zn2+(aq).

D) Zn(s).

E) Zn(NO3)2(aq).

Diff: 2

Section: 5.3

64) Nitric acid reacts with copper metal according to the unbalanced equation,

Cu(s) + HNO3(aq) → Cu(NO3)2(aq) + NO2(g) + H2O

Which is correct?

A) The nitrate ion is the reducing agent, and it is reduced to water.

B) The product of the reduction reaction is NO2.

C) The product of the reduction reaction is Cu(NO3)2.

D) Copper is the oxidizing agent, and it is reduced to Cu(NO3)2.

E) Both water and copper are reduced.

Diff: 2

Section: 5.3

65) Magnesium metal reacts with aqueous sulfuric acid solution to produce aqueous magnesium sulfate and hydrogen gas. In the course of the reaction, which element undergoes an increase in oxidation number?

A) hydrogen

B) magnesium

C) oxygen

D) sulfur

E) both magnesium and hydrogen

Diff: 2

Section: 5.3

66) The reaction of potassium metal and which one of the following ions could be used to produce the most electrical current, per mole of potassium?

Hint: Look at the activity series.

A) Ag+

B) H+

C) Mn+

D) Sr2+

E) Rb+

Diff: 3

Section: 5.3

67) The most reactive metals are those of

A) Group IA (Group 1).

B) Group IIA (Group 2).

C) Group IIIA (Group 13).

D) Group IB (Group 11).

E) Group IIB (Group 12).

Diff: 1

Section: 5.4

68) The activity series of metals is

Au < Ag < Cu < Sn < Cd < Zn < Al < Mg < Na < Cs

Based on this list, which element below would undergo oxidation most readily?

A) Ag

B) Al

C) Cu

D) Cd

E) Zn

Diff: 1

Section: 5.4

69) The activity series of metals is

Au < Ag < Cu < Sn < Cd < Zn < Al < Mg < Na < Cs

Based on this list, which element below would undergo oxidation most readily?

A) Mg

B) Al

C) Cu

D) Cd

E) Zn

Diff: 1

Section: 5.4

70) The activity series of metals is

Au < Ag < Cu < Sn < Cd < Zn < Al < Mg < Na < Cs

Based on this list, which element below would undergo oxidation least readily?

A) Mg

B) Al

C) Cu

D) Cd

E) Zn

Diff: 1

Section: 5.4

71) The activity series of metals is

Au < Ag < Cu < Sn < Cd < Zn < Al < Mg < Na < Cs

Based on this list, which element below would undergo oxidation least readily?

A) Ag

B) Al

C) Cu

D) Cd

E) Zn

Diff: 1

Section: 5.4

72) The activity series of metals is

Au < Ag < Cu < Sn < Cd < Zn < Al < Mg < Na < Cs

Based on this list, which element below would react most readily with a 0.10 M aqueous solution of hydrofluoric acid?

A) Ag

B) Sn

C) Cu

D) Cd

E) Zn

Diff: 2

Section: 5.4

73) The activity series of metals is

Au < Ag < Cu < Sn < Cd < Zn < Al < Mg < Na < Cs

Based on this list, which element below would react most readily with a 0.10 M aqueous solution of hydrochloric acid?

A) Au

B) Sn

C) Cu

D) Al

E) Mg

Diff: 2

Section: 5.4

74) Three metallic elements, copper, gold and zinc, can be distinguished from one another on the basis of how they react with two strong acids, HNO3(aq) and HCl(aq). Which set below, using the abbreviations R (for reaction occurs) and NR (for no reaction) correctly describes what occurs?

A) Au: HCl(R), HNO3(NR) Cu: HCl(R), HNO3(NR) Zn: HCl(R), HNO3(NR)

B) Au: HCl(NR), HNO3(NR) Cu: HCl(R), HNO3(R) Zn: HCl(R), HNO3(NR)

C) Au: HCl(NR), HNO3(NR) Cu: HCl(NR), HNO3(R) Zn: HCl(R), HNO3(R)

D) Au: HCl(NR), HNO3(NR) Cu: HCl(R), HNO3(R) Zn: HCl(NR), HNO3(R)

E) Au: HCl(NR), HNO3(NR) Cu: HCl(R), HNO3(NR) Zn: HCl(R), HNO3(R)

Diff: 2

Section: 5.4

75) Three metallic elements, copper, magnesium and gold, can be distinguished from one another on the basis of how they react with two strong acids, HNO3(aq) and HCl(aq). Which set below, using the abbreviations R (for reaction occurs) and NR (no reaction) correctly describes what occurs?

A) Au: HCl(R), HNO3(NR) Cu: HCl(R), HNO3(NR) Mg: HCl(R), HNO3(NR)

B) Au: HCl(NR), HNO3(NR) Cu: HCl(R), HNO3(R) Mg: HCl(R), HNO3(NR)

C) Au: HCl(NR), HNO3(NR) Cu: HCl(R), HNO3(R) Mg: HCl(NR), HNO3(R)

D) Au: HCl(NR), HNO3(NR) Cu: HCl(R), HNO3(NR) Mg: HCl(R), HNO3(R)

E) Au: HCl(NR), HNO3(NR) Cu: HCl(NR), HNO3(R) Mg: HCl(R), HNO3(R)

Diff: 2

Section: 5.4

76) The least reactive metals are those of

A) Group IA (Group 1)

B) Group IIA (Group 2)

C) Group IIIA (Group 13)

D) Group IB (Group 11)

E) Group IIB (Group 12)

Diff: 2

Section: 5.4

77) The activity series of metals is

Au < Ag < Cu < Sn < Cd < Zn < Al < Mg < Na < Cs

Which reaction below does not occur spontaneously upon mixing the reagents shown?

A) Cd(s) + Al3+(aq) → Cd2+(aq) + Al(s)

B) Cd(s) + Cu2+(aq) → Cd2+(aq) + Cu(s)

C) Zn(s) + Cu2+(aq) → Zn2+(aq) + Cu(s)

D) Al(s) + Ag+(aq) → Al3+(aq) + Ag(s)

E) Cu(s) + Au3+(aq) → Cu2+(aq) + Au(s)

Diff: 2

Section: 5.4

78) The activity series of metals is

Au < Ag < Cu < Sn < Cd < Zn < Al < Mg < Na < Cs

Which reaction below does not occur spontaneously upon mixing the reagents shown?

A) Al(s) + Cd2+(aq) → Al3+(aq) + Cd(s)

B) Mg(s) + Cu2+(aq) → Mg2+(aq) + Cu(s)

C) Zn(s) + Ag+(aq) → Zn2+(aq) + Ag(s)

D) Zn(s) + Al3+(aq) → Zn2+(aq) + Al(s)

E) Na(s) + Au3+(aq) → Na+(aq) + Au(s)

Diff: 2

Section: 5.4

79) The activity series of metals is

Au < Ag < Cu < Sn < Cd < Zn < Al < Mg < Na < Cs

Which reaction below occurs spontaneously upon mixing the reagents shown?

A) Sn(s) + Zn2+(aq) → Sn2+(aq) + Zn(s)

B) Ag(s) + Mg2+(aq) → Ag+(aq) + Mg(s)

C) Zn(s) + Au3+(aq) → Zn2+(aq) + Au(s)

D) Ag(s) + Zn2+(aq) → Ag+(aq) + Zn(s)

E) Sn(s) + Al3+(aq) → Sn2+(aq) + Al(s)

Diff: 2

Section: 5.4

80) The activity series of metals is

Au < Ag < Cu < Sn < Cd < Zn < Al < Mg < Na < Cs

Which reaction below occurs spontaneously upon mixing the reagents shown?

A) Ag(s) + Zn2+(aq) → Ag+(aq) + Zn(s)

B) Ag(s) + Cd2+(aq) → Ag+(aq) + Cd(s)

C) Zn(s) + Mg2+(aq) → Zn2+(aq) + Mg(s)

D) Ag(s) + Mg2+(aq) → Ag+(aq) + Mg(s)

E) Sn(s) + Cu2+(aq) → Sn2+(aq) + Cu(s)

Diff: 2

Section: 5.4

81) Which element would react most rapidly with water?

A) Ag

B) K

C) Cu

D) Na

E) Rb

Diff: 2

Section: 5.4

82) Which element would react most rapidly with water?

A) K

B) Cd

C) Cs

D) Na

E) Zn

Diff: 2

Section: 5.4

83) Which element would be the least likely to react, if at all, with water?

A) Ca

B) Al

C) Cu

D) Na

E) Zn

Diff: 2

Section: 5.4

84) A partial activity series is: Au < Ag < Cu < H2 < Sn < Cd < Fe < Mn. Which combination of metals is likely to be produced when each of the following compounds is made to react with solid Cd metal:

Cd(NO3)2(aq); Fe(NO3)2(aq); HNO3(aq); Cu(NO3)2(aq); Sn(NO3)2(aq)?

Hint: In the partial activity series above, Mn is the most reactive and Au is the least reactive.

A) Cd, Fe

B) Cu, Cd

C) Cu, Fe

D) Fe, Sn

E) Sn, Cu

Diff: 3

Section: 5.4

85) A partial activity series is: Au < Ag < Cu < H2 < Sn < Cd < Fe < Mn. Which metal(s) is/are NOT likely to be produced when each of the following compounds is made to react with Cd metal:

Cd(NO3)2(aq); Fe(NO3)2(aq); HNO3(aq); Cu(NO3)2(aq); Sn(NO3)2(aq); AgNO3(aq)?

Hint: In the partial activity series above, Mn is the most reactive and Au is the least reactive.

A) Cu, Sn

B) Sn, Ag

C) Cu

D) Fe, Cd

E) Ag, Cu

Diff: 3

Section: 5.4

86) When the hydrocarbon, C8H16, undergoes complete combustion, which is an oxidation-reduction reaction, a specific set of products is formed. If you write the equation for the reaction and balance it, the sum of the coefficients for the reagents in the balanced equation will be:

Hint: Complete combustion of a hydrocarbon in oxygen always yields carbon dioxide and water vapor.

A) 17

B) 19

C) 21

D) 26

E) 29

Diff: 3

Section: 5.5

87) When the carbohydrate, C12H22O11, undergoes complete combustion, which is an oxidation-reduction reaction, a specific set of products are formed. If you write the equation for the reaction and balance it, the sum of the coefficients for the reagents in the balanced equation will be:

Hint: Complete combustion of a hydrocarbon in oxygen always yields carbon dioxide and water vapor.

A) 24

B) 35

C) 36

D) 47

E) 83

Diff: 3

Section: 5.5

88) When the carbohydrate, C12H22O11, undergoes complete combustion, the reducing agent in the reaction is

A) oxygen.

B) the carbohydrate.

C) hydrogen.

D) carbon.

E) carbon dioxide.

Diff: 2

Section: 5.5

89) When glucose, C6H12O6, undergoes complete combustion, the species that is reduced is

A) oxygen.

B) glucose.

C) hydrogen.

D) carbon.

E) carbon dioxide.

Diff: 2

Section: 5.5

90) What is the equation that best describes the oxidation of iron by oxygen in the presence of moisture?

Hint: Be sure to consider the oxidation numbers when determining the equation.

A) Fe2+(aq) + H2O(aq) + O2(g) → FeO(s) + H2(g) + O2(g)

B) 4 H+(aq) + 2Fe(s) + O2(g) → 2H2O(l) + 2Fe2+ (aq)

C) 4Fe(s) + 3O2(g) + 2xH2O → 2Fe2O3·xH2O(s)

D) Fe(s) + 2H2O(aq) + O2(g) → Fe(OH)2(s) + H2O2(l)

E) 2Fe(s) + 6H2O(aq) + O2(g) → 2Fe(OH)3(s) + 3H2(g) + O2(g)

Diff: 3

Section: 5.5

91) When hydrocarbons or coal contain sulfur what is formed during the complete combustion?

Hint: Consider the products of a complete combustion reaction with something containing sulfur. What should always be produced?

A) H2S

B) HS

C) HSO2

D) SO2

E) SO

Diff: 3

Section: 5.5

92) The oxidation of aluminum occurs slowly, due to the formation of which substance on the surface of the metal?

Hint: Consider the reaction of aluminum and oxygen.

A) AlCl3(s)

B) Al2(SO4)3(s)

C) Al(NO3)3(s)

D) Al2O3(s)

E) Al(OH)3(s)

Diff: 3

Section: 5.5

93) When aluminum is exposed to the environment it does not corrode in the same way as iron. Which of the following best explains why?

Hint: Look at the chemical properties of iron and aluminum.

A) Aluminum quickly oxidizes at the surface and forms a protective coating that prevents further oxidation.

B) Aluminum is not as reactive as iron, and does not react with molecular oxygen.

C) Aluminum is not easily reduced, so it is not reduced by exposure to oxygen.

D) Aluminum normally treated with a polymer coating that prevents oxidation.

E) Aluminum reacts with water to form a hydride coating that protects the rest of the aluminum from oxidation.

Diff: 3

Section: 5.5

94) The amount of iron in a sample can be determined by a titration using dichromate ion, Cr2O72-, in acidic solution. The iron is first converted to Fe2+, which is then titrated by the dichromate ion. The reaction is:

6 Fe2+(aq) + Cr2O72-(aq) + 14 H+ → 6 Fe3+(aq) + 2 Cr3+(aq) + 7 H2O

How many grams of iron are present in a sample if it required 42.7 mL of 0.0180 M Na2Cr2O7(aq) solution for the titration described by the redox equation above?

A) 0.043 g

B) 0.258 g

C) 3.61 g

D) 7.07 g

E) 7.15 g

Diff: 2

Section: 5.6

95) The strength of a hydrogen peroxide, H2O2, solution can be determined by titration with permanganate solution. The reaction is:

2 MnO4-(aq) + 5 H2O2(aq) + 6 H+ → 5O2(g) + 2 Mn2+(aq) + 8 H2O

If it required 80.0 mL of 0.0220 molar MnO4-(aq) solution to titrate 5.0 mL of a H2O2(aq) solution, what is the molarity of the H2O2(aq) solution?

A) 0.14 M

B) 0.18 M

C) 0.35 M

D) 0.62 M

E) 0.88 M

Diff: 2

Section: 5.6

96) Zinc reacts with the permanganate ion to form Zn2+(aq) ions and Mn2+(aq) ions. The reaction is:

5 Zn(s) + 2 MnO4-(aq) + 16 H+ → 5 Zn2+(aq) + 2 Mn2+(aq) + 8 H2O

How many grams of zinc are required to completely react with 100.0 mL of a 0.0150 M solution of KMnO4(aq)?

A) 0.0392 g

B) 0.0981 g

C) 0.245 g

D) 10.2 g

E) 43.9 g

Diff: 2

Section: 5.6

97) SO2 is a dangerous air pollutant, which can harm human lungs. The quantity of SO2 in air can be determined by the reaction,

2 MnO4-(aq) + 5 SO2(g) + 2 H2O → 5 SO42-(aq) + 2 Mn2+(aq) + 4 H+

It required 185 mL of 0.0200 M MnO4-(aq) solution to completely react with all of the SO2 in a sample of air. How many grams of SO2 were in the sample?

A) 3.70 g

B) 9.25 g

C) 0.237 g

D) 0.0948 g

E) 0.593 g

Diff: 2

Section: 5.6

98) You can dissolve a penny using nitric acid, HNO3. The reaction

Cu(s) + 4 HNO3(aq) → Cu(NO3)2(aq) + 2 NO2(g) + 2 H2O(l)

is used to dissolve copper metal. If there is 1.000 g of copper to be dissolved, and instructions say to use four times as much acid as the required amount, how many mL (to the nearest mL) of 15.0 M nitric acid would be required to dissolve the copper?

Hint: Don't forget the coefficients in the balanced reaction above when performing your calculations with nitric acid.

A) 4 mL

B) 5 mL

C) 10 mL

D) 17 mL

E) 25 mL

Diff: 3

Section: 5.6

99) Fe2+(aq) reacts with MnO4-(aq) ion in acidic solution to yield Fe3+(aq) ions and Mn2+(aq) ions.

5Fe2+(aq) + MnO4-(aq) + 8H+ → 5 Fe3+(aq) + Mn2+(aq) + 4H2O

Melanterite is a greenish mineral, and can be found on the walls of mines. A sample of melanterite, FeSO4·7H2O, was analyzed for purity using this reaction by titration of an aqueous solution of the sample. One such sample required 47.35 mL of 0.0175350 M permanganate solution to completely titrate all the iron in the sample by the reaction shown above. How much did the sample weigh, if it was in fact pure melanterite?

Hint: Watch your units carefully at each step of the problem.

A) 0.596 g

B) 0.184 g

C) 0.461 g

D) 1.154 g

E) 4.87 g

Diff: 3

Section: 5.6

100) Fe2+(aq) reacts with MnO4-(aq) ion in acidic solution to yield Fe3+(aq) ions and Mn2+(aq) ions.

5Fe2+(aq) + MnO4-(aq) + 8H+ → 5Fe3+(aq) + Mn2+(aq) + 4H2O

Melanterite is a greenish mineral, and can be found on the walls of mines. A sample of melanterite, FeSO4·7H2O, was analyzed for purity using this reaction by titration of an aqueous solution of the sample. One such sample required 56.15 mL of 0.01301 M permanganate solution to completely titrate all the iron in the sample by the reaction shown above. How much did the sample weigh, if it was in fact pure melanterite?

Hint: Watch your units carefully at each step of the problem.

A) 1.015 g

B) 0.203 g

C) 0.555 g

D) 4.851 g

E) 0.407 g

Diff: 3

Section: 5.6

101) What is the compound formed in the reaction between hydrogen sulfide and silver metal, which is responsible for the dull film on the silver metal when it tarnishes in air?

A) Ag2SO4

B) AgHSO4

C) Ag2S

D) Ag2CO3

E) Ag2SO3

Diff: 2

Section: Chemistry Outside the Classroom 5.1

102) Which metal(s) can be used to reduce compounds of silver to silver metal?

A) Hg

B) Au

C) Ag

D) Al

E) Hg and Au

Diff: 2

Section: Chemistry Outside the Classroom 5.1

103) Which is the most likely reaction to reduce silver ions to silver metal?

Hint: Silver metal refers to silver (Ag) in the solid phase.

A) 3Ag(s) + Au3+(aq) → 3Ag+(aq) + Au(s)

B) Al(s) + 3Ag+(aq) → Al3+(aq) + 3Ag(s)

C) Hg(s) + 2Ag+(aq) → Hg2+(aq) + 2Ag(s)

D) Au(s) + 3Ag+(aq) → Au3+(aq) + 3Ag(s)

E) 2Ag(s) + Hg2+(aq) → 2Ag+(aq) + Hg(s)

Diff: 3

Section: Chemistry Outside the Classroom 5.1

104) The oxidation number of Cr in Na2Cr2O7 is

Diff: 1

Section: 5.1

105) The oxidation number of N in HNO3 is

Diff: 1

Section: 5.1

106) The oxidation number of V in VOCl3 is ________.

Diff: 1

Section: 5.1

107) The oxidation number of C in CH2Cl2 is ________.

Hint: Assign oxidation numbers to hydrogen and chlorine first before determining carbon.

Diff: 3

Section: 5.1

108) The oxidation number of Mn in Mn2O7 is ________.

Diff: 1

Section: 5.1

109) The oxidation number of N in NO2- is ________.

Diff: 2

Section: 5.1

110) The oxidation number of P in HPO42- is ________.

Diff: 2

Section: 5.1

111) The oxidation number of N in NO2 is ________.

Diff: 2

Section: 5.1

112) The oxidation number of S in S2O32- is ________.

Diff: 2

Section: 5.1

113) Is the following, Cr2O72 → Cr3+, an oxidation or a reduction half-reaction?

Diff: 1

Section: 5.1

114) Is the following, NO3 → NO, an oxidation or a reduction half-reaction?

Diff: 2

Section: 5.1

115) Is the following, PbO2 → PbO, an oxidation or a reduction half-reaction?

Diff: 2

Section: 5.1

116) Is the following, C2O42 → CO32, an oxidation or a reduction half-reaction?

Diff: 2

Section: 5.1

117) Which substance in the reaction

BrO3-(aq) + 3 Zn(s) + 6 H+(aq) → Br-(aq) + 3 Zn2+(aq) + 3 H2O(l)

is the oxidizing agent?

Diff: 2

Section: 5.1

118) Which substance in the reaction

5 H2O(l) + 4 Cl2(g) + S2O32-(aq) → 2 SO42-(aq) + 8 Cl-(aq) + 10 H+(aq)

is the reducing agent?

Diff: 2

Section: 5.1

119) Identify the reducing agent in the chemical reaction

Cd + NiO2 + 2H2O → Cd(OH)2 + Ni(OH)2.

Diff: 2

Section: 5.1

120) When H2O2 behaves as a reducing agent, the most likely product formed from it is ________.

Hint: Write out an example equation with H2O2 being oxidized to see the result.

Diff: 3

Section: 5.1

121) When concentrated nitric acid behaves as an oxidizing agent, how does the oxidation number of N change?

Hint: An oxidizing agent is reduced.

Diff: 3

Section: 5.1

122) When the equation, Al(s) + NO3-(aq) → NO(g) + Al3+(aq) is balanced for an acidic solution, the Al/NO3- ratio is ________.

Hint: H+ are present in an acidic solution.

Diff: 3

Section: 5.2

123) When the equation, Al(s) + NO3-(aq) → NO(g) + Al3+(aq) is balanced for an acidic solution, the sum of ALL the coefficients is ________.

Hint: Do not neglect to include electrons when balancing redox reactions.

Diff: 3

Section: 5.2

124) When the equation, Zn(s) + NO3-(aq) → NH4+(aq) + Zn2+(aq) is balanced for an acidic solution, the Zn/NO3- ratio is ________.

Hint: Do not neglect to include electrons when balancing redox reactions.

Diff: 3

Section: 5.2

125) When the equation, Zn(s) + NO3-(aq) → NH4+(aq) + Zn2+(aq) is balanced for an acidic solution, the sum of ALL the coefficients is ________.

Hint: Do not neglect to include electrons when balancing redox reactions.

Diff: 3

Section: 5.2

126) Balance the redox reaction below in acidic solution.

PbO2(s) + I-(aq) → Pb2+(aq) + I2(s)

When balanced, what is the sum of all the coefficients?

Hint: Do not neglect to include electrons when balancing redox reactions.

Diff: 3

Section: 5.2

127) Balance the redox reaction below in basic solution.

PbO2(s) + I-(aq) → Pb2+(aq) + I2(s)

What is the coefficient of OH- in the final balanced equation?

Hint: Consider your oxidation numbers when balancing redox reactions.

Diff: 3

Section: 5.2

128) Balance the redox reaction below in acidic solution.

Cl2(g) → Cl-(aq) + ClO-(aq)

When balanced, what is the sum of all the coefficients?

Hint: Consider your oxidation numbers when balancing redox reactions.

Diff: 3

Section: 5.2

129) Balance the redox reaction below in basic solution.

Cl2(g) → Cl-(aq) + ClO-(aq)

What is the coefficient of OH- in the final balanced equation?

Hint: Consider your oxidation numbers when balancing redox reactions.

Diff: 3

Section: 5.2

130) When a metal displaces hydrogen from a nonoxidizing strong acid, which substance is the oxidizing agent?

Diff: 2

Section: 5.3

131) When a metal displaces hydrogen from a nonoxidizing strong acid, which substance is the reducing agent?

Diff: 2

Section: 5.3

132) When a copper metal reacts with aqueous nitric acid, which substance is the oxidizing agent?

Diff: 2

Section: 5.3

133) When a metal is reacted with nitric acid, which element in nitric acid is reduced?

Diff: 2

Section: 5.3

134) A partial activity series of metals is: Au < Ag < Cu < Pb < Sn. Which metal is most easily oxidized: Au, Pb, Ag?

Diff: 1

Section: 5.4

135) A partial activity series of metals is: Au < Ag < Cu < Pb < Sn. Which ion is most easily reduced: Au3+, Pb2+, Ag+?

Diff: 2

Section: 5.4

136) A partial activity series is: Pb < Sn < Co < Fe < Zn. Which metal will react least readily with nonoxidizing acids to produce hydrogen gas?

Hint: Oxidation is a loss of electrons.

Diff: 3

Section: 5.4

137) A partial activity series is: Au < Ag < Cu < H2 < Pb < Sn < Co < Fe. Which metal will be produced when each of the following compounds reacts with Sn metal:

Co(NO3)2(aq); Fe(NO3)2(aq); HNO3(aq); Cu(NO3)2(aq); Sn(NO3)2(aq)?

Diff: 2

Section: 5.4

138) A partial activity series is: Au < Pt < Ag < Cu < H2 < Sn < Co < Fe < Mg. List all metals in this partial activity series that would NOT react with a solution of HCl.

Diff: 2

Section: 5.4

139) A partial activity series is: Au < Pt < Ag < Cu < H2 < Sn < Co < Fe < Mg. List the metals in this partial series that would react with a solution of Sn2+ ions.

Diff: 2

Section: 5.4

140) A partial activity series is: Au < Pt < Ag < Cu < H2 < Sn < Co < Fe < Mg. Based on this series, which of the following solutions would cause a reaction with Cu(s)?

Ag+(aq) Cu2+(aq) Co2+(aq) Mg2+(aq)

Diff: 2

Section: 5.4

141) When a metal reacts with oxygen gas, which substance is the reducing agent?

Diff: 1

Section: 5.5

142) What two products are formed when CH4 reacts with a very limited supply of molecular oxygen?

Hint: Oxygen must be conserved in the products.

Diff: 3

Section: 5.5

143) Nitrogen combines readily with molecular oxygen to form six known nitrogen oxides. The formulas of the nitrogen oxides in which nitrogen has an oxidation number of 4, are ________.

Diff: 2

Section: 5.5

144) When hydrocarbons undergo combustion, they form water and another product depending on the conditions. In the presence of excess oxygen, ________ is formed while in a somewhat limited supply of oxygen, ________ will form. If there is very limited amounts of oxygen, ________ will form.

Diff: 2

Section: 5.5

145) Organic compounds that contain the element ________ in their molecular structure require less oxygen than organic structures with similar masses in order to undergo complete combustion.

Diff: 2

Section: 5.5

146) A solution was made by taking 2.500 g of KMnO4 and dissolving it in enough water to make 1.000 liter of solution. This solution was used to titrate H2C2O4·2H2O, which can be readily obtained in high purity. In acidic media, the reaction is:

2 MnO4-(aq) + 5 H2C2O4(aq) + 6 H+ → 10 CO2(g) + 2 Mn2+(aq) + 8 H2O

How many mL of this solution are required to titrate a 0.480 g sample of H2C2O4·2H2O?

Hint: Remember to use moles as an intermediary when performing your stoichiometry calculations for the titration.

Diff: 3

Section: 5.6

147) In order for an oxidation reaction to occur, a reduction reaction must also take place.

Diff: 1

Section: 5.1

148) An oxidation reaction involves the loss of electrons.

Diff: 1

Section: 5.1

149) The reaction, HCl(aq) + Na2CO3(aq) → NaCl(aq) + H2O(l) + CO2(g), involves changes in oxidation number and is therefore classified as a redox reaction.

Diff: 1

Section: 5.1

150) The reaction, Al(s) + HClO4(aq) → Al(ClO4)3(aq) + H2(g), involves changes in oxidation numbers and is therefore classified as a redox reaction.

Diff: 1

Section: 5.1

151) The reaction, Cl2(g) + NaBr(aq) → NaCl(aq) + Br2(l), involves changes in oxidation number and is therefore classified as a redox reaction.

Diff: 1

Section: 5.1

152) The reaction, AgNO3(aq) + NH4Br(aq) → AgBr(s) + NH4NO3(aq), involves changes in oxidation number and is therefore classified as a redox reaction.

Diff: 1

Section: 5.1

153) The reaction, NiS(s) + O2(g) → NiO(s) + SO2(g), involves changes in oxidation number and is therefore classified as a redox reaction.

Diff: 2

Section: 5.1

154) The following reaction describes the decomposition of NaHCO3, baking soda:

2NaHCO3 → Na2CO3 + CO2 + H2O

This is not an oxidation-reduction reaction, since nothing is oxidized or reduced.

Diff: 2

Section: 5.1

155) In the equation, Cu2+ (aq) + Al(s) → Cu(s) + Al3+(aq), there is one mole of each species, hence, it is balanced.

Diff: 1

Section: 5.2

156) Balancing a redox reaction in acidic media is no different than balancing the same reaction in a basic media.

Diff: 1

Section: 5.2

157) In the equation, 2H+ (aq) + Zn(s) → H2(g) + Zn2+(aq), the H+ is the oxidizing agent and Zn is the reducing agent.

Diff: 1

Section: 5.3

158) Hot concentrated sulfuric acid is a good oxidizing agent.

Diff: 1

Section: 5.3

159) All strong acids are also oxidizing acids.

Diff: 1

Section: 5.3

160) Oxidizing acids will react with more metals than nonoxidizing acids.

Diff: 1

Section: 5.3

161) Magnesium metal will displace hydrogen from nonoxidizing acids.

Diff: 1

Section: 5.4

162) The activity series of metals is

Au < Ag < Cu < Sn < Cd < Zn < Al < Mg < Na < Cs

This means that cadmium will displace aluminum from an aqueous solution of aluminum sulfate.

Diff: 1

Section: 5.4

163) The metals of Group IA undergo reduction more readily than those in any other groups of the periodic table.

Diff: 1

Section: 5.4

164) When hydrocarbon compounds undergo combustion, the carbon is always converted into carbon dioxide.

Diff: 1

Section: 5.5

165) When hydrocarbon compounds undergo combustion, the hydrogen is always converted into water.

Diff: 1

Section: 5.5

166) The following chemical equation shows how water can be produced.

H2(g) + ½ O2(g) → H2O(l)

In the reaction, hydrogen is the species which is reduced.

Diff: 1

Section: 5.5

167) When organic compounds that contain sulfur undergo complete combustion with oxygen, one of the products is hydrogen sulfide.

Diff: 2

Section: 5.5

168) KMnO4 in acidic media is a powerful oxidizing agent, which is often used in redox titrations.

Diff: 1

Section: 5.6

169) Hydrogen peroxide, H2O2, is a powerful oxidizing agent, which has many medical and industrial uses.

Diff: 2

Section: 5.6

170) What is the oxidation number of sulfur in the compound, FeS2?

Diff: 1

Section: 5.1

171) Rust is a hydrated compound formed between iron and oxygen, in the presence of water. The formula is approximately Fe2O3•32H2O. What is the oxidation number of the iron ion?

Diff: 1

Section: 5.1

172) In which compound does sulfur have the highest oxidation number?

A) H2S

B) SO2

C) SCl2

D) H2SO3

E) Na2SO4

Diff: 1

Section: 5.1

173) Consider the following species: Cl2, Cl-, ClO-, ClO2-, ClO3-, and ClO4-. What is the oxidation number of Cl atom in each species, respectively?

A) (-1, +1, +1, +3, +5, +7)

B) (0, +1, -1, -3, +5, +7)

C) (0, -1, +1, +3, +5, +7)

D) (0, +1, +1, +3, +5, +7)

E) (-1, -1, +1, +3, +5, 0).

Diff: 2

Section: 5.1

174) Consider the oxidation states of hydrogen in the following compounds: LiH, NaH, KH, MgH2, CaH2, NiH, CuH, ZnH2, HF, HCl, HBr, HI, H2O, H2S, H2Se, and H2Te. What statement is true?

A) All of the metal compounds have H in the oxidation state of -1, while the nonmetal compounds have H in the oxidation state of +1.

B) In general, metals form covalent compounds with hydrogen, whereas, nonmetals form molecular compounds with hydrogen.

C) In general, metals form molecular compounds with hydrogen, whereas, nonmetals form ionic compounds with hydrogen.

D) All of the metal compounds have H in the oxidation state of +1, while the nonmetal compounds have H in the oxidation state of -1.

E) Hydrogen can only react with nonmetallic elements.

Diff: 2

Section: 5.1

175) In a series of chemical test reactions, the following observations were made when several metallic element samples were treated with 3.00 M hydrochloric acid solution. Zn: metal dissolves, hydrogen gas is emitted. Cu: no reaction. Ag: no reaction. Mg: metal dissolves, hydrogen gas is emitted. Mn: metal dissolves, hydrogen gas is emitted. Which statement below is true?

A) Mg, Mn, Zn are more reactive than Ag, Cu; but less reactive than H2.

B) Mg, Mn, Zn are less reactive than Ag, Cu; but more reactive than H2.

C) Mg, Mn, Zn are more reactive than Ag, Cu, and H2.

D) Mg, Mn, Zn are less reactive than Ag, Cu, and H2.

E) These observations are insufficient to form any judgment about relative reactivity of any of the elements tested.

Diff: 2

Section: 5.4

176) The activity series of metals is

Au < Ag < Cu < Sn < Cd < Zn < Al < Mg < Na < Cs

Which reaction below does not occur spontaneously upon mixing the reagents shown?

A) Cd(s) + Al3+(aq) → Cd2+(aq) + Al(s)

B) Cd(s) + Cu2+(aq) → Cd2+(aq) + Cu(s)

C) Zn(s) + Cu2+(aq) → Zn2+(aq) + Cu(s)

D) Al(s) + Ag+(aq) → Al3+(aq) + Ag(s)

E) Cu(s) + Au3+(aq) → Cu2+(aq) + Au(s)

Diff: 2

Section: 5.4

177) Ethanol, C2H5OH, is often found in gasoline. In these cases it is often produced from ethanol plants that turn corn into ethanol. The cost-benefit analysis of this process is often a topic of debate. Explain why some ethanol in gasoline could aid in the efficiency of your engine.

Diff: 2

Section: 5.5

178) Coal is still a large part of the world's energy supply, but not all coal is the same. Some coal deposits contain high amounts of sulfur. Explain how burning coal with high sulfur content, in form of SO2,could be harmful to the environment.

Diff: 2

Section: 5.5

179) A solution was made by taking 2.500 g of KMnO4 and dissolving it in enough water to make 1.000 liter of solution. This solution was used to titrate H2C2O4·2H2O, a very pure substance. In acidic media, the reaction is

MnO4-(aq) + H2C2O4(aq) + ________→ CO2(g) + Mn2+(aq) + _______

How many mL of this solution are required to titrate a 0.480 g sample of H2C2O4·2H2O?

Hint: Remember to use moles as an intermediary when performing your stoichiometry calculations for the titration.

Diff: 3

Section: 5.6

180) It is proposed to measure the CO gas present in air samples by passing the gas through a solution of potassium permanganate. The reaction that occurs is,

____MnO4-(aq) + ____CO(g) + ________ → ____CO2(g) + ____Mn2+(aq) + ________

In a trial run, it required 102 liters of air containing CO (no other substances that would react with permanganate were present) to completely decolorize 250 mL of 0.0150 M MnO4-(aq) solution in a scrubber. If air weighs 1.29 g/liter, what is the percent by weight of CO in the air?

Hint: Make sure your equation is balanced and pay attention to your units throughout the problem.

Diff: 3

Section: 5.6

181) A student working on her research project will do a synthesis which involves bubbling chlorine gas through the aqueous reaction mixture in a closed system. The outlet from the system goes through a scrubber, which contains some sodium thiosulfate solution. The sodium thiosulfate will react with the chlorine passing through the scrubber to produce harmless chloride ion and sulfate ion. This prevents the chlorine from going up the exhaust system and polluting the atmosphere on campus grounds. The reaction is:

Cl2(g) + S2O32-(aq) → SO42-(aq) + Cl-(aq)

The reaction calls for 15.5 grams of chlorine gas. The student wants enough thiosulfate in the scrubber to be able to handle twice this amount to be on the safe side. How many grams of crystal sodium thiosulfate (which is actually sodium thiosulfate pentahydrate) should the student weigh out for use in the scrubber?

Hint: Make sure you balance the equation and focus on units.

Diff: 3

Section: 5.6

182) A student will prepare a significant quantity of a gold compound which will be used in her research project, as well as other projects in her research group. The first step calls for the reaction of the gold metal with aqua regia (a 3:1 v/v mix of concentrated hydrochloric acid and concentrated nitric acid). In her procedure, she is to use 6 times as much aqua regia as the stoichiometric quantity required. A graduate student performed the calculation and indicated that aqua regia mixed according to directions has a nitrate concentration of 3.08 M and a chloride concentration of 6.96 M, while the hydrogen ion concentration is 10.04 M. The reaction is,

Au(s) + NO3-(aq) + Cl-(aq) + H+(aq) → NO2(g) + AuCl4-(aq) + H2O(l)

The piece of gold wire, that is, the starting material, weighs 9.562 grams. Calculate the volume, in mL, of aqua regia which is required, based on the consideration stated above.

Hint: Balance your reaction and be sure to determine the limiting reagent.

Diff: 3

Section: 5.6

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