Deck 18: Electrochemistry

Question 1

Which of the following is the weakest oxidizing agent?

A)Sn²⁺(aq)
B)Cr³⁺(aq)
C)Sn⁴⁺(aq)
D)Cr(s)
E)Sn(s)

Answer 1

Cr(s)

Question 2

Which of the following is the strongest reducing agent?

A)Na(s)
B)Li⁺(aq)
C)Ca(s)
D)Ca²⁺(aq)
E)Li(s)

Answer 2

Li(s)

Question 3

What is undergoing reduction in the redox reaction represented by the following cell notation?
$\quad$$\quad$$\quad$ Fe(s)| Fe³⁺(aq) $\|$ Cl₂(g)| Cl^- (aq)| Pt(s)

A)Fe(s)
B)Fe³⁺(aq)
C)Cl₂(g)
D)Cl^- (aq)
E)Pt(s)

Answer 3

Cl₂(g)

Question 4

Describe how water can be made to be a good conductor of electrical current.

A)use pure water
B)heat the water
C)add salt
D)chill the water
E)vaporize the water

Question 5

Determine the redox reaction represented by the following cell notation:
$\quad$$\quad$ Mg(s)| Mg²⁺(aq) $\|$ Cu²⁺(aq)| Cu(s)

A)Cu(s)+ Mg²⁺(aq)? Mg(s)+ Cu²⁺(aq)
B)Mg(s)+ Cu²⁺(aq)? Cu(s)+ Mg²⁺(aq)
C)2Mg(s)+ Cu²⁺(aq)? Cu(s)+ 2Mg²⁺(aq)
D)2Cu(s)+ Mg²⁺(aq)? Mg(s)+ 2Cu²⁺(aq)
E)3Mg(s)+ 2Cu²⁺(aq)? 2Cu(s)+ 3Mg²⁺(aq)

Question 6

What is undergoing reduction in the redox reaction represented by the following cell notation?
$\quad$$\quad$$\quad$ Pb(s)| Pb²⁺(aq) $\|$ H⁺(aq)| H₂(g)| Pt(s)

A)H₂(g)
B)H⁺(aq)
C)Pb²⁺(aq)
D)Pb(s)
E)Pt(s)

Question 7

What is the reducing agent in the redox reaction represented by the following cell notation?
$\quad$$\quad$$\quad$ Sn(s)| Sn²⁺(aq) $\|$ Ag⁺(aq)| Ag(s)

A)Sn(s)
B)Ag⁺(aq)
C)Sn²⁺(aq)
D)Ag(s)
E)Pt(s)

Question 8

What is the reducing agent in the redox reaction represented by the following cell notation?
$\quad$$\quad$$\quad$ Ni(s)| Ni²⁺(aq) $\|$ Ag⁺(aq)| Ag(s)

A)Ni(s)
B)Ni²⁺(aq)
C)Ag⁺(aq)
D)Ag(s)
E)Pt(s)

Question 9

Determine the cell notation for the redox reaction given below:
$\quad$$\quad$ Pb(s)+ 2H⁺ (aq)? Pb²⁺(aq)+ H₂(g)

A)H⁺(aq)| H₂(g)| Pt(s) $\|$ Pb(s)| Pb²⁺(aq)
B)H₂(g)| H⁺(aq)| Pt(s) $\|$ Pb²⁺(aq)| Pb(s)
C)Pb²⁺(aq)| Pb(s) $\|$ H₂(g)| H⁺(aq)| Pt(s)
D)Pb(s)| Pb²⁺(aq) $\|$ H⁺(aq)| H₂(g)| Pt(s)
E)Pb(s)| H₂(g) $\|$ Pb²⁺(aq)| H⁺(aq)| Pt(s)

Question 10

Which of the following is the strongest reducing agent?

A)Sn²⁺(aq)
B)Cr³⁺(aq)
C)Sn⁴⁺(aq)
D)Cr(s)
E)Sn(s)

Question 11

What is undergoing oxidation in the redox reaction represented by the following cell notation?
$\quad$$\quad$$\quad$ Fe(s)| Fe³⁺(aq) $\|$ Cl₂(g)| Cl^- (aq)| Pt(s)

A)Fe(s)
B)Fe³⁺(aq)
C)Cl₂(g)
D)Cl^- (aq)
E)Pt(s)

Question 12

Determine the cell notation for the redox reaction given below:
$\quad$$\quad$$\quad$ 3Cl₂(g)+ 2Fe(s)? 6Cl^- (aq)+ 2Fe³⁺(aq)

A)Cl₂(g)| Cl^- (aq)| Pt(s) $\|$ Fe(s)| Fe³⁺(aq)
B)Cl^- (aq)| Cl₂(g)| Pt(s) $\|$ Fe³⁺(aq) | Fe(s)
C)Fe³⁺(aq)| Fe(s) $\|$ Cl^- (aq)| Cl₂(g)| Pt(s)
D)Fe(s)| Cl₂(g) $\|$ Fe³⁺(aq)| Cl^- (aq)| Pt(s)
E)Fe(s)| Fe³⁺(aq) $\|$ Cl₂(g)| Cl^- (aq)| Pt(s)

Question 13

How many electrons are transferred in the following reaction? (The reaction is unbalanced.) I₂(s)+ Fe(s)→ Fe³⁺(aq)+ I^- (aq)

A)1
B)2
C)6
D)3
E)4

Question 14

Which of the following is TRUE about standard electrode potentials?

A)E°_cell ^{is negative for spontaneous reactions.}
B)Electrons will flow from a more positive electrode to a more negative electrode.
C)The electrode potential of the standard hydrogen electrode is exactly zero.
D)E°_cell is the sum between standard reduction potentials of the anode and the cathode.
E)The electrode in any half-cell with a greater tendency to undergo reduction is negatively charged relative to the standard hydrogen electrode and therefore has E° < 0.

Question 15

Determine the cell notation for the redox reaction given below:
$\quad$$\quad$$\quad$ Sn(s)+ 2Ag⁺ (aq)? Sn²⁺(aq)+ 2Ag(s)

A)Ag⁺(aq)| Ag(s) $\|$ Sn(s)| Sn²⁺(aq)
B)Ag(s)| Ag⁺(aq) $\|$ Sn²⁺(aq)| Sn(s)
C)Sn(s)| Sn²⁺(aq) $\|$ Ag⁺(aq)| Ag(s)
D)Sn²⁺(aq)| Sn(s) $\|$ Ag(s)| Ag⁺(aq)
E)Sn(s)| Ag(s) $\|$ Sn²⁺(aq)| Ag⁺(aq)

Question 16

What is the oxidizing agent in the redox reaction represented by the following cell notation?
$\quad$$\quad$$\quad$ Ni(s)| Ni²⁺(aq) $\|$ Ag⁺(aq)| Ag(s)

A)Ni(s)
B)Ni²⁺(aq)
C)Ag⁺(aq)
D)Ag(s)
E)Pt(s)

Question 17

What is the oxidizing agent in the redox reaction represented by the following cell notation?
$\quad$$\quad$$\quad$ Sn(s)| Sn²⁺(aq) $\|$ Ag⁺(aq)| Ag(s)

A)Sn(s)
B)Ag⁺(aq)
C)Sn²⁺(aq)
D)Ag(s)
E)Pt(s)

Question 18

Which of the following is the strongest reducing agent?

A)Al(s)
B)Zn(s)
C)Mg(s)
D)Al³⁺(aq)
E)Mg²⁺(aq)

Question 19

What is undergoing oxidation in the redox reaction represented by the following cell notation?
$\quad$$\quad$$\quad$ Pb(s)| Pb²⁺(aq) $\|$ H⁺(aq)| H₂(g)| Pt(s)

A)H₂(g)
B)H⁺(aq)
C)Pb²⁺(aq)
D)Pb(s)
E)Pt(s)

Question 20

How many electrons are transferred in the following reaction? (The reaction is unbalanced.) Fe²⁺(aq)+ K(s)→ Fe(s)+ K⁺(aq)

A)1
B)2
C)3
D)4
E)6

Question 21

Use the standard half-cell potentials listed below to calculate the standard cell potential for the following reaction occurring in an electrochemical cell at 25 °C.(The equation is balanced.) 2K(s)+ I₂(s)→ 2K⁺ (aq)+ 2I^- (aq)
K⁺(aq)+ e^- → K (s)E° = -2.93 V
I₂(s)+ 2 e^- → 2 I^- (aq)E° = +0.54 V

A)+6.40 V
B)+1.85 V
C)-5.32 V
D)+3.47 V
E)+5.32 V

Question 22

Use the standard half-cell potentials listed below to calculate the standard cell potential for the following reaction occurring in an electrochemical cell at 25 °C.(The equation is balanced.) 3Cl₂(g)+ 2Fe(s)→ 6Cl^- (aq)+ 2Fe³⁺(aq)
Cl₂(g)+ 2 e^- → 2Cl^- (aq)E° = +1.36 V
Fe³⁺(aq)+ 3 e^- → Fe(s)E° = -0.04 V

A)+4.16 V
B)-1.40 V
C)-1.32 V
D)+1.32 V
E)+1.40 V

Question 23

Use the standard half-cell potentials listed below to calculate the standard cell potential for the following reaction occurring in an electrochemical cell at 25 °C.(The equation is balanced.) Sn(s)+ 2Ag⁺ (aq)→ Sn²⁺(aq)+ 2Ag(s)
Sn²⁺(aq)+ 2 e^- → Sn(s)E° = -0.14 V
Ag⁺ (aq)+ e^- → Ag(s)E° = +0.80 V

A)+1.74 V
B)+0.94 V
C)+1.08 V
D)-1.08 V
E)-1.74 V

Question 24

Use the standard half-cell potentials listed below to calculate the standard cell potential for the following reaction occurring in an electrochemical cell at 25 °C.(The equation is balanced.) Mg(s)+ Cu²⁺(aq)→ Cu(s)+ Mg²⁺(aq)
Mg²⁺(aq)+ 2 e^- → Mg(s)E° = -2.38 V
Cu²⁺(aq)+ 2 e^- → Cu(s)E° = +0.34 V

A)+2.04 V
B)-2.04 V
C)+2.72 V
D)-1.36 V
E)+1.36 V

Question 25

If the standard reduction potential of Zn is -0.76 V,which of the following statements about a cell whose half-cells are Zn²⁺/Zn and SHE is correct?

A)SHE will be the cell's cathode,Zn(s)will be the cell's anode,and the measured cell potential will be 0.76 V.
B)SHE will be the cell's anode,Zn(s)will be the cell's cathode,and the measured cell potential will be 0.76 V.
C)SHE will be the cell's cathode,Zn(s)will be the cell's anode,and the measured cell potential will be -0.76 V.
D)SHE will be the cell's cathode,Zn²⁺(aq)will be the cell's anode,and the measured cell potential will be 0.76 V.
E)H⁺(aq)will be the cell's cathode,Zn²⁺(aq)will be the cell's anode,and the measured cell potential will be 0.76 V.

Question 26

Which of the following reactions would be the most spontaneous at 298 K?

A)A + 2 B → C; E°_cell = +0.98 V
B)A + B → 2 C; E°_cell = -0.030 V
C)A + B → 3 C; E°_cell = +0.15 V
D)A + B → C; E°_cell = +1.22 V
E)A + B → C; E°_cell = -1.22 V

Question 27

Which of the following is the strongest oxidizing agent?

A)H₂O₂(aq)
B)Fe³⁺(aq)
C)ClO₂(g)
D)I₂(s)
E)Fe(s)

Question 28

Which of the following is the strongest oxidizing agent?

A)Al(s)
B)Zn²⁺(aq)
C)Mg(s)
D)Al³⁺(aq)
E)Mg²⁺(aq)

Question 29

Use the standard half-cell potentials listed below to calculate the standard cell potential for the following reaction occurring in an electrochemical cell at 2 5°C.(The equation is balanced.) Pb(s)+ Br₂(l)→ Pb²⁺(aq)+ 2 Br⁻(aq)
Pb²⁺(aq)+ 2 e^- → Pb(s)E° = -0.13 V
Br₂(l)+ 2 e^- → 2 Br^- (aq)E° = +1.07 V

A)+1.20 V
B)+0.94 V
C)-0.94 V
D)-1.20 V
E)-0.60 V

Question 30

Which of the following is the weakest reducing agent?

A)Br₂(l)
B)Au³⁺(aq)
C)Ag(s)
D)Br^- (aq)
E)Au(s)

Question 31

Which of the following metals will dissolve in HCl?

A)Au; E°(Au³⁺/Au)= +1.50V
B)Ag; E°(Ag⁺/Ag)= +0.80V
C)Cu; E°(Cu²⁺/Cu)= +0.34V
D)Al; E°(Al³⁺/Al)= -1.66V
E)Pt; E°(Pt²⁺/Pt)= +1.19V

Question 32

Which of the following is the weakest oxidizing agent?

A)H₂O₂(aq)
B)Fe³⁺(aq)
C)ClO₂(g)
D)I₂(s)
E)Fe(s)

Question 33

Which of the following is the strongest oxidizing agent?

A)MnO₂(s)
B)Cl^- (aq)
C)Cu⁺(aq)
D)SO₄^2-(aq)
E)MnO₄^- (aq)

Question 34

Determine which of the following pairs of reactants will result in a spontaneous reaction at 25 °C.

A)Pb²⁺(aq)+ Cu(s); if E°(Pb²⁺/Pb)= -0.13V and E°(Cu²⁺/Cu)= +0.16V
B)Ag⁺(aq)+ Br^- (aq); if E°(Ag⁺/Ag)= 0.80V and E°(Br₂/Br^-)= +1.09V
C)Li⁺(aq)+ Al(s); if E°(Li⁺/Li)= -3.04V and E°(Al³⁺/Al)= -1.66V
D)Fe³⁺(aq)+ Ni(s); if E°(Fe³⁺/Fe)= -0.04V and E°(Ni²⁺/Ni)= -0.23V
E)Cd²⁺(aq)+ I^-(aq); if E°(Cd²⁺/Cd)= -0.40V and E°(I₂/I^-)= + 0.54V

Question 35

Which of the following is the strongest oxidizing agent?

A)Br₂(l)
B)Au³⁺(aq)
C)Ag(s)
D)Br^- (aq)
E)Au(s)

Question 36

Determine which of the following pairs of reactants will result in a spontaneous reaction at 25 °C.

A)Sn⁴⁺(aq)+ Mg(s); if E°(Sn⁴⁺/Sn²⁺)= +0.15V and E°(Mg²⁺/Mg)= -2.37V
B)Cr³⁺(aq)+ Ni(s); if E°(Cr³⁺/Cr)= -0.73V and E°(Ni²⁺/Ni)= -0.23V
C)Zn(s)+ Na⁺(aq); if E°(Zn²⁺/Zn)= -0.76V and E°(Na⁺/Na)= -2.71V
D)Fe(s)+ Ba²⁺(aq); if E°(Fe³⁺/Fe)= -0.04V and E°(Ba²⁺/Ba)= -2.90V
E)Ni²⁺(aq)+ NO(g); if E°(Ni²⁺/Ni)= -0.23V and E°(NO₃^-/NO)= +0.96V

Question 37

Which of the following metals will dissolve in nitric acid but not hydrochloric acid?

A)Fe; E°(Fe²⁺/Fe)= -0.45V
B)Pb; E°(Pb²⁺/Pb)= -0.13V
C)Cu; E°(Cu²⁺/Cu)= +0.34V
D)Sn; E°(Sn²⁺/Sn)= -0.14V
E)Ni; E°(Ni²⁺/Ni)= -0.23V

Question 38

Determine which of the following pairs of reactants will result in a spontaneous reaction at 25 °C.

A)I^-(aq)+ Zn²⁺(aq); if E°(I₂/I^-)= + 0.54V and E°(Zn²⁺/Zn)= -0.76V
B)Ca(s)+ Mg²⁺(aq); if E°(Ca²⁺/Ca)= -2.76V and E°(Mg²⁺/Mg)= -2.37V
C)H₂(g)+ Cd²⁺(aq); if E°(Cd²⁺/Cd)= -0.40V
D)Ag(s)+ Sn²⁺(aq); if E°(Ag⁺/Ag)= + 0.80V and E°(Sn²⁺/Sn)= -0.14V
E)Ag⁺(aq)+ Mn²⁺(aq); if E°(Ag⁺/Ag)= + 0.80V and E°(MnO₄^-/Mn²⁺)= +1.51V

Question 39

Which of the following statements is true for the cell diagram below?
$\quad$ Zn(s)| Zn²⁺(aq) $\|$ Cu²⁺(aq)| Cu(s)

A)Zn is oxidized,Cu is reduced; the single vertical lines represent phase boundaries while the two vertical lines represent a salt bridge.
B)Zn²⁺is oxidized,Cu is reduced; the single vertical lines represent phase boundaries while the two vertical lines represent a salt bridge.
C)Zn is oxidized,Cu²⁺ is reduced; the single vertical lines represent phase boundaries while the two vertical lines represent a salt bridge.
D)Zn is oxidized,Cu²⁺ is reduced; the single vertical lines represent salt bridges while the two vertical lines represent a phase boundary.
E)Zn is reduced,Cu²⁺ is oxidized; the single vertical lines represent phase boundaries while the two vertical lines represent a salt bridge.

Question 40

Which of the following metals will dissolve in nitric acid but not hydrochloric acid?

A)Cd; E°(Cd²⁺/Cd)= -0.40V
B)Cr; E°(Cr³⁺/Cr)= -0.73V
C)Mn; E°(Mn²⁺/Mn)= -1.18V
D)Ag; E°(Ag⁺/Ag)= +0.80V
E)Al; E°(Al³⁺/Al)= -1.66V

Question 41

Calculate the cell potential for the following unbalanced reaction that takes place in an electrochemical cell at 25 °C when [ $\mathrm { Cr } ^ { 3 }$ ] = 0.945 M and [ $\mathrm { Zn } ^ { 2 + }$ ] = 1.37 M
$\quad$$\quad$ Zn(s)+ $\mathrm { Cr } ^ { 3+ }$ (aq)? $\mathrm { Zn } ^ { 2 + }$ (aq)+ Cr(s)
E°(Zn²⁺/Zn)= -0.76 V and E°(Cr³⁺/Cr)= -0.73 V

A)+0.03 V
B)-0.03 V
C)-1.18 V
D)+1.18 V
E)+0.49 V

Question 42

Calculate the cell potential for the following unbalanced reaction that takes place in an electrochemical cell at 25 °C when [ $\mathrm { Cr } ^ { 3+ }$ ] = 2.00 M and [ $\mathrm { Zn } ^ { 2 + }$ ] = 0.00300 M
$\quad$$\quad$ Zn(s)+ $\mathrm { Cr } ^ { 3+ }$ (aq)? $\mathrm { Zn } ^ { 2 + }$ (aq)+ Cr(s)
E°(Zn²⁺/Zn)= -0.76 V and E°(Cr³⁺/Cr)= -0.73 V

A)+0.06 V
B)-0.19 V
C)+1.30 V
D)+0.02 V
E)+0.11 V

Question 43

Calculate the cell potential for the following unbalanced reaction that takes place in an electrochemical cell at 25 °C when [ $\mathrm { Mg } ^ { 2 + }$ ] = 3.20 M and [ $\mathrm { Fe } ^ { 3 + }$ ] = 0.000100 M
$\quad$$\quad$$\quad$ Mg(s)+ $\mathrm { Fe } ^ { 3 + }$ (aq)? $\mathrm { Mg } ^ { 2 + }$ (aq)+ Fe(s)
E°(Mg²⁺/Mg)= -2.37 V and E°(Fe³⁺/Fe)= -0.036 V

A)-2.24 V
B)+2.24 V
C)+1.24 V
D)-1.24 V
E)+2.14 V

Question 44

Calculate the cell potential for the following unbalanced reaction that takes place in an electrochemical cell at 25 °C when [ $\mathrm { Mg } ^ { 2 + }$ ] = 0.500 M and [ $\mathrm { Fe } ^ { 3 + }$ ] = 2.00 M
$\quad$$\quad$ Mg(s)+ $\mathrm { Fe } ^ { 3 + }$ (aq)? $\mathrm { Mg } ^ { 2 + }$ (aq)+ Fe(s)
E°(Mg²⁺/Mg)= -2.37 V and E°(Fe³⁺/Fe)= -0.036 V

A)+2.09 V
B)-3.18 V
C)+2.35 V
D)+0.36 V
E)-1.51 V

Question 45

Calculate the cell potential for the following reaction that takes place in an electrochemical cell at 25 °C:
$\quad$$\quad$$\quad$ Sn(s)| Sn²⁺(aq,0.010 mol L^-1) $\|$ Ag⁺(aq,1.00 mol L^-1)| Ag(s)
E°(Sn²⁺/Sn)= -0.14 V and E°(Ag⁺/Ag)= +0.80 V

A)+1.18 V
B)-1.18 V
C)+1.00 V
D)+0.94 V
E)-0.94 V

Question 46

Calculate the cell potential for the following unbalanced reaction that takes place in an electrochemical cell at 25 °C when [ $\mathrm { Mg } ^ { 2 + }$ ] = 0.914 M and [ $\mathrm { Fe } ^ { 3 + }$ ] = 0.0230 M
$\quad$$\quad$ Mg(s)+ $\mathrm { Fe } ^ { 3 + }$ (aq)? $\mathrm { Mg } ^ { 2 + }$ (aq)+ Fe(s)
E°(Mg²⁺/Mg)= -2.37 V and E°(Fe³⁺/Fe)= -0.036 V

A)+2.32 V
B)+2.30 V
C)-2.32 V
D)-2.30 V
E)+1.23 V

Question 47

Calculate the cell potential for the following reaction that takes place in an electrochemical cell at 25 °C:
$\quad$$\quad$$\quad$ Mg(s)| Mg²⁺(aq,2.74 mol L^-1) $\|$ Cu²⁺(aq,0.0033 mol L^-1)| Cu(s)
E°(Mg²⁺/Mg)= -2.37 V and E°(Cu²⁺/Cu)= +0.34 V

A)-2.80 V
B)+2.62 V
C)+2.71 V
D)+2.12 V
E)-1.94 V

Question 48

Calculate the cell potential for the following reaction that takes place in an electrochemical cell at 25 °C:
$\quad$$\quad$$\quad$ Sn(s)| Sn²⁺(aq,1.8 mol L^-1) $\|$ Ag⁺(aq,0.055 mol L^-1)| Ag(s)
E°(Sn²⁺/Sn)= -0.14 V and E°(Ag⁺/Ag)= +0.80 V

A)-0.94 V
B)-0.85 V
C)+1.02 V
D)+0.98 V
E)+0.86 V

Question 49

Use the provided reduction potentials to calculate Δ_rG° for the following redox reaction: 2Al(s)+ 3Mg²⁺(aq)→ 2Al³⁺(aq)+ 3Mg(s)
E°(Al³⁺/Al)= -1.66 V and E°(Mg²⁺/Mg)= -2.37 V

A)+4.1 × 10² kJ mol^-1
B)+1.4 × 10² kJ mol^-1
C)-2.3 × 10² kJ mol^-1
D)-7.8 × 10² kJ mol^-1
E)+6.8 × 10² kJ mol^-1

Question 50

Calculate the cell potential for the following reaction that takes place in an electrochemical cell at 25 °C:
$\quad$$\quad$$\quad$ Sn(s)| Sn²⁺(aq,0.022 mol L^-1) $\|$ Ag⁺(aq,2.7 mol L^-1)| Ag(s)
E°(Sn²⁺/Sn)= -0.14 V and E°(Ag⁺/Ag)= +0.80 V

A)+1.01 V
B)-0.83 V
C)+1.31 V
D)+0.01 V
E)-0.66 V

Question 51

Use the provided reduction potentials to calculate the equilibrium constant (K)for the following balanced redox reaction at 25 °C: 2Al(s)+ 3Mg²⁺(aq)→ 2Al³⁺(aq)+ 3Mg(s)
E°(Al³⁺/Al)= -1.66 V and E°(Mg²⁺/Mg)= -2.37 V

A)1.1 × 10⁷²
B)8.9 × 10^-70
C)9.7 × 10^-73
D)1.0 × 10²⁴
E)4.6 × 10³¹

Question 52

Use the tabulated half-cell potentials to calculate the equilibrium constant (K)for the following balanced redox reaction at 25 °C: 3I₂(s)+ 2Fe(s)→ 2Fe³⁺(aq)+ 6I^- (aq)
E°(I₂/I^-)= + 0.54 V and E°(Fe³⁺/Fe)= -0.036 V

A)3.5 × 10^-59
B)1.1 × 10¹⁷
C)2.4 × 10⁵⁸
D)8.9 × 10^-18
E)1.7 × 10²⁹

Question 53

Use the provided reduction potentials to calculate Δ_rG° for the following balanced redox reaction: Pb²⁺(aq)+ Cu(s)→ Pb(s)+ Cu²⁺(aq)
E°(Pb²⁺/Pb)= -0.13 V and E°(Cu²⁺/Cu)= +0.34 V

A)-41 kJ mol^-1
B)-0.47 kJ mol^-1
C)+46 kJ mol^-1
D)+91 kJ mol^-1
E)-21 kJ mol^-1

Question 54

Use the tabulated half-cell potentials to calculate the equilibrium constant (K)for the following balanced redox reaction at 25 °C: Pb²⁺(aq)+ Cu(s)→ Pb(s)+ Cu²⁺(aq)
E°(Pb²⁺/Pb)= -0.13 V and E°(Cu²⁺/Cu)= +0.34 V

A)7.9 × 10^-8
B)8.9 × 10⁷
C)7.9 × 10¹⁵
D)1.3 × 10^-16
E)1.1 × 10^-8

Question 55

Calculate the cell potential for the following reaction that takes place in an electrochemical cell at 25 °C:
$\quad$$\quad$$\quad$ Sn(s)| Sn²⁺(aq,0.100 mol L^-1) $\|$ Ag⁺(aq,0.200 mol L^-1)| Ag(s)
E°(Sn²⁺/Sn)= -0.14 V and E°(Ag⁺/Ag)= +0.80 V

A)-2.68 V
B)-0.03 V
C)+0.95 V
D)+0.93 V
E)+2.10 V

Question 56

Calculate the cell potential for the following unbalanced reaction that takes place in an electrochemical cell at 25 °C when [ $\mathrm { Mg } ^ { 2 + }$ ] = 0.000612 M and [ $\mathrm { Fe } ^ { 3 + }$ ] = 1.29 M
$\quad$$\quad$ Mg(s)+ $\mathrm { Fe } ^ { 3 + }$ (aq)? $\mathrm { Mg } ^ { 2 + }$ (aq)+ Fe(s)
E°(Mg²⁺/Mg)= -2.37 V and E°(Fe³⁺/Fe)= -0.036 V

A)-3.42 V
B)+3.42 V
C)-4.32 V
D)+2.43 V
E)+3.24 V

Question 57

Which of the following reactions would have the smallest value of K at 298 K?

A)A + B → C; E°_cell = +1.22 V
B)A + 2 B → C; E°_cell = +0.98 V
C)A + B → 2 C; E°_cell = -0.030 V
D)A + B → 3 C; E°_cell = +0.15 V
E)A + B → C; E°_cell = -0.015 V

Question 58

Calculate the cell potential for the following unbalanced reaction that takes place in an electrochemical cell at 25 °C when [ $\mathrm { Mg } ^ { 2 + }$ ] = 1.10 M and [ $\mathrm { Fe } ^ { 3 + }$ ] = 1.10 M
$\quad$$\quad$$\quad$ Mg(s)+ $\mathrm { Fe } ^ { 3 + }$ (aq)? $\mathrm { Mg } ^ { 2 + }$ (aq)+ Fe(s)
E°(Mg²⁺/Mg)= -2.37 V and E°(Fe³⁺/Fe)= -0.036 V

A)+2.33 V
B)-3.23 V
C)+1.48 V
D)+2.22 V
E)+0.68 V

Question 59

Use the provided reduction potentials to calculate Δ_rG° for the following balanced redox reaction: 3I₂(s)+ 2Fe(s)→ 2Fe³⁺(aq)+ 6I^- (aq)
E°(I₂/I^-)= + 0.54 V and E°(Fe³⁺/Fe)= -0.036 V

A)-1.1 × 10² kJ mol^-1
B)+4.9 × 10¹ kJ mol^-1
C)-9.7 × 10¹ kJ mol^-1
D)+2.3 × 10² kJ mol^-1
E)-3.3 × 10² kJ mol^-1

Question 60

Identify the characteristics of a spontaneous reaction.

A)Δ_rG° > 0
B)ΔE°_cell < 0
C)K < 0
D)ΔE°_cell > 0
E)K = 0

Question 61

Predict the species that will be reduced first if a mixture of molten salts containing the following ions undergoes electrolysis: Na⁺,Ca²⁺,Cl^-,Br^-,F^-

A)Na⁺
B)Cl^-
C)Ca²⁺
D)Br^-
E)F^-

Question 62

How much copper,in g,can be plated from a solution of $\mathrm { Cu } ^ { 2 + }$ if 3.14 A is applied for 45 minutes?

A)2.79 g
B)1.85 g
C)11.2 g
D)0.283 g
E)7.64 g

Question 63

Nickel can be plated from aqueous solution according to the following half-reaction.How long would it take (in min)to plate 29.6 g of nickel at 4.7 A? Ni²⁺(aq)+ 2 e ^- → Ni(s)

A)1.7 × 10² min
B)5.9 × 10² min
C)3.5 × 10² min
D)4.8 × 10² min
E)6.2 × 10² min

Question 64

What mass of silver can be plated onto an object in 33.5 minutes at 8.70 A of current? Ag⁺ (aq)+ e^- → Ag(s)

A)19.6 g
B)0.326 g
C)9.78 g
D)3.07 g
E)0.102 g

Question 65

What is the reaction at the anode in a breathalyzer?

A)Ethanol is oxidized to acetic acid.
B)Acetic acid is reduced to ethanol.
C)Oxygen is reduced.
D)Hydrogen is oxidized.
E)Ethanol is oxidized to acetaldehyde.

Question 66

What mass of aluminum can be plated onto an object in 755 minutes at 5.80 A of current?

A)73.5 g
B)24.5 g
C)220.g
D)147 g
E)8.17 g

Question 67

Identify the battery that is used as a common flashlight battery.

A)dry-cell battery
B)lithium-ion battery
C)lead-acid storage battery
D)NiCad battery
E)fuel cell

Question 68

Identify the components of a fuel cell.

A)nickel-metal hydride
B)lithium-ion
C)hydrogen-oxygen
D)nickel-cadmium
E)zinc-manganese

Question 69

Calculate the cell potential for the following reaction that takes place in an electrochemical cell at 25 °:
$\quad$$\quad$ Cu(s)| Cu²⁺(aq,0.0032 mol L^-1) $\|$ Cu²⁺(aq,4.48 mol L^-1)| Cu(s)
E°(Cu²⁺/Cu)= +0.34 V

A)0.00 V
B)+0.093 V
C)+0.34 V
D)+0.186 V
E)+0.052 V

Question 70

What is the reaction at the cathode in a breathalyzer?

A)Ethanol is oxidized to acetic acid.
B)Acetic acid is reduced to ethanol.
C)Oxygen is reduced.
D)Hydrogen is oxidized.
E)Ethanol is oxidized to acetaldehyde.

Question 71

How much chromium,in g,can be plated from a solution of $\mathrm { Cr } ^ { 3 }$ if 2.72 A is applied for 15 minutes?

A)1.32 g
B)6.51 × $10 ^ { - 3 }$ g
C)0.937 g
D)0.440 g
E)4.67 g

Question 72

Calculate the cell potential for the following reaction that takes place in an electrochemical cell at 25 °:
$\quad$$\quad$$\quad$ Fe(s)| Fe³⁺(aq,0.0011 mol L^-1) $\|$ Fe³⁺(aq,2.33 mol L^-1)| Fe(s)
E°(Fe³⁺/Fe)= -0.036 V

A)+0.066 V
B)-0.036 V
C)0.00 V
D)-0.099 V
E)+0.20 V

Question 73

Identify the battery that is in most automobiles.

A)dry-cell battery
B)lithium-ion battery
C)lead-acid storage battery
D)NiCad battery
E)fuel cell

Question 74

What is the shorthand notation that represents the following galvanic cell reaction? Pb(s)+ Cu(NO₃)₂(aq)→ Pb(NO₃)₂(aq)+ Cu(s)

A)Pb(s)| Pb²⁺(aq)|| Cu²⁺(aq)| Cu(s)
B)Cu(s)| Cu²⁺(aq)|| Pb²⁺(aq)| Pb(s)
C)Pb(s)| NO₃^-(aq)|| NO₃^-(aq)| Cu(s)
D)Cu(s)| Cu(NO₃)₂(aq)|| Pb(NO₃)₂(aq)| Pb(s)

Question 75

In the presence of which of the following would iron be under the highest risk of rusting?

A)salt only
B)moisture only
C)acid only
D)salt and moisture combined
E)salt,moisture,and acid together

Question 76

Predict the species that will be oxidized first if a mixture of molten salts containing the following ions undergoes electrolysis: Cu²⁺,Mg²⁺,Cl^-,Br^-,F^-

A)Cl^-
B)F^-
C)Cu²⁺
D)Mg²⁺
E)Br^-

Question 77

Identify the battery type that has a high overcharge tolerance.

A)NiCad battery
B)lithium-ion battery
C)nickel-metal hydride battery
D)lead-acid storage battery
E)zinc-manganese battery

Question 78

Calculate the cell potential for the following reaction that takes place in an electrochemical cell at 25 °C:
$\quad$$\quad$$\quad$ Al(s)| Al³⁺(aq,0.115 mol L^-1) $\|$ Al³⁺(aq,3.89 mol L^-1)| Al(s)
E°(Al³⁺/Al)= -1.66 V

A)+1.66 V
B)+0.060 V
C)0.00 V
D)+0.090 V
E)+0.030 V

Question 79

Identify the metal if during a 1.000 hour long 2 electron electrolysis reaction 8.388 g of metal is deposited using a constant current of 4.000 A.

A)Al
B)Mn
C)Cd
D)Au
E)Ag

Question 80

Predict the species that will be reduced first if a mixture of molten salts containing the following ions undergoes electrolysis: Zn²⁺,Fe³⁺,Mg²⁺,Br^-,I^-

A)Zn²⁺
B)Mg²⁺
C)Br^-
D)Fe³⁺
E)I^-