Which one of the following is not a redox reaction?
Al(OH)4-(aq) + 4H+(aq) � Al3+(aq) + 4H2O(l)
Consider the reaction
CuO(s) + H2(g) � Cu(s) + H2O(l)
In this reaction, which substances are the oxidant (oxidizing agent) and reductant (reducing agent), respectively?
CuO and H2
When the following redox equation is balanced with smallest whole number coefficients, the coefficient for nitrogen dioxide will be _____.
I2(s) + HNO3(aq) � HIO3(aq) + NO2(g) + H2O(l)
10
When the following redox equation is balanced with smallest whole number coefficients, the coefficient for Sn(OH)3- will be _____.
Bi(OH)3(s) + Sn(OH)3-(aq) �
Sn(OH)62-(aq) + Bi(s) (basic solution)
3
Consider the following redox equation
Mn(OH)2(s) + MnO4-(aq) �
MnO42-(aq) (basic solution)
When the equation is balanced with smallest whole number coefficients, what is the coefficient for OH-(aq) and on which side of the equation is OH-(aq) present?
6, reactant side
Which of the following statements about voltaic and electrolytic cells is correct?
The cathode is labeled as positive (+) in a voltaic cell but negative (-) in an electrolytic cell.
Which of the following solids is commonly used as an inactive electrode in electrochemical cells?
graphite
A voltaic cell is prepared using copper and silver. Its cell notation is shown below.
Cu(s) | Cu2+(aq) || Ag+(aq) | Ag(s)
Which of the following processes occurs at the cathode?
Ag+(aq) + e- � Ag(s)
A voltaic cell prepared using aluminum and nickel has the following cell notation.
Al(s) | Al3+(aq) || Ni2+(aq) | Ni(s)
Which of the following represents the correctly balanced spontaneous reaction equation for the cell?
3Ni2+(aq) + 2Al(s) � 2Al3+(aq) + 3Ni(s)
What is the E�cell for the cell represented by the combination of the following half-reactions?
2Hg2+(aq) + 2e- Hg22+(aq); E�= 0.92 V
Cr3+
(aq) + 3e- Cr(s); E�= -0.74 V
1.66 V
The redox reaction of peroxydisulfate with iodide has been used for many years as part of the iodine clock reaction which introduces students to kinetics. If E�cell
= 1.587 V and E� of the cathode half-cell is 0.536 V, what is E� of the anode half-cell?
S
?
Given that E� for X + e- � Y is greater than E� for A + 2e- � B, it is correct to say that, under standard conditions
B will reduce X
Examine the following half-reactions and select the strongest oxidizing agent among the substances.
[PtCl4]2-(aq) + 2e- Pt(s) + 4Cl-(aq); E� = 0.755 V
RuO4(s) + 8H+(aq) + 8e- Ru(s) + 4H2O(l); E� = 1.038 V
FeO42-(aq) + 8H+(aq) + 3e- Fe3+(aq) + 4H2O(l); E�
H4XeO6(aq)
Examine the following half-reactions and select the weakest oxidizing agent among the species listed.
AuBr4-(aq) + 3e- Au(s) + 4Br-(aq); E� = 0.854 V
Mn2+(aq) + 2e- Mn(s); E� = -1.185 V
K+(aq) + e- K(s); E� = -2.931 V
F2O(aq) + 2H+(aq) + 4e- 2F-(aq) + H2O
K+(aq)
Examine the following half-reactions and select the strongest reducing agent among the species listed.
PbI2(s) + 2e- Pb(s) + 2I-(aq); E� = -0.365 V
Ca2+(aq) + 2e- Ca(s); E� = -2.868 V
Pt2+(aq) + 2e- Pt(s); E� = 1.18 V
Br2(l) + 2e- 2Br-(aq); E� = 1.066 V
Ca(s)
Calculate E�cell
and indicate whether the overall reaction shown is spontaneous or nonspontaneous.
Co3+(aq) + e- Co2+(aq); E� = 1.82 V MnO4-(aq) + 2H2O(l) + 3e- MnO2(s) + 4OH-(aq); E� = 0.59 V
Overall reaction:
MnO4-(aq) + 2H2O(l) + 3Co2+(aq) � MnO2(s) +
E�cell = -1.23 V, nonspontaneous
When metal A is placed in a solution of metal ions B2+, a reaction occurs between A and B2+, and metal ions A2+ appear in the solution. When metal B is placed in acid solution, gas bubbles form on its surface. When metal A is placed in a solution of metal
B(s) + C2+(aq) � C(s) + B2+(aq)
Which of the following conditions is most likely to apply to a fully-charged secondary cell?
Q<K
A battery is considered "dead" when
Q=K
What is the value of the equilibrium constant for the cell reaction below at 25�C? E�cell
= 0.61 V
2Cr(s) + 3Pb2+(aq) 3Pb(s) + 2Cr3+(aq)
7.4 � 1061
Consider the reaction in the lead-acid cell
Pb(s) + PbO2(s) + 2H2SO4(aq) � 2PbSO4(aq) + 2H2O(l)
for which E�cell = 2.04 V at 298 K. DG� for this reaction is
-3.94 � 102 kJ
The value of E�cell for the reaction
2Cr3+(aq) + 6Hg(l) � 2Cr(s) + 3Hg22+(aq)
is 1.59 V. Calculate DG� for the reaction.
-921 kJ
Calculate DG� for the reaction of iron(II) ions with one mole of permanganate ions.
MnO4-(aq) + 8H+(aq) + 5e- Mn2+(aq) + 4H2O(l); E� = 1.51 V
Fe3+(aq) + e- Fe2+(aq); E�= 0.77 V
-357 kJ
The value of the equilibrium constant for the reaction of nickel(II) ions with cadmium metal is 1.17 � 105. Calculate DG� for the reaction at 25�C.
-28.9 kJ
Consider the reaction of iodine with manganese dioxide
3I2(s) + 2MnO2(s) + 8OH-(aq) 6I-(aq) + 2MnO4-(aq) + 4H2O(l)
The equilibrium constant for the overall reaction is 8.30 � 10-7. Calculate E�cell
for the reaction at 25�C.
-0.060 V
A voltaic cell consists of a Mn/Mn2+ electrode (E�= -1.18 V) and a Fe/Fe2+ electrode (E�= -0.44 V). Calculate [Fe2+] if [Mn2+] = 0.050 M and Ecell = 0.78 V at 25�C.
1.1 M
A voltaic cell consists of a Ag/Ag+ electrode (E� = 0.80 V) and a Fe2+/Fe3+ electrode (E� = 0.77 V) with the following initial molar concentrations: [Fe2+] = 0.30 M; [Fe3+] = 0.10 M; [Ag+] = 0.30 M. What is the equilibrium concentration of Fe3+? (Assume t
0.17 M
A concentration cell consists of two Zn/Zn2+ electrodes. The electrolyte in compartment A is 0.10 M Zn(NO3)2
and in compartment B is 0.60 M Zn(NO3)2. What is the voltage of the cell at 25�C?
0.023 V
Which, if any, of the following metals would be capable of acting as a sacrificial anode when used with iron pipe? E�Fe = -0.44 V; all E� values refer to the M2+/M half-cell reactions.
chromium, Cr, E� = -0.74 V
What mass of silver will be formed when 15.0 A are passed through molten AgCl for 25.0 minutes?
25.2 g
A solution is prepared by dissolving 32.0 g of NiSO4 in water. What current would be needed to deposit all of the nickel in 5.0 hours?
2.2 A