|AP Chemistry - Electrochemistry Worksheet #5|
|1.||Give the equation
that relates the standard cell potential to the standard free energy change
for a reaction.
|2.||What is the
maximum amount of work, expressed in joules, that can be obtained from the
discharge of a silver oxide battery if 1.00 g of Ag2O reacts?
Eo for the cell reaction is 1.50 V.
+ 2 OH-(aq) ----> Zn(OH)2(s) + 2 e-
The overall net cell reaction is
|3.||A watt is a
unit of electrical power equal to one/joule/second. (1 watt = 1 J/s). How
many hours can a calculator drawing 5 X 10-4 W be operated by
a mercury battery having a cell potential equal to 1.34 V if a mass
of 1.00 g of HgO is available as the cathode?
Zn(s) + 2 OH-(aq) ----> Zn(OH)2(s)
+ 2 e-
The net reaction is
Zn(s) + HgO(s) ---->
ZnO(s) + Hg(l)
half-reactions and their standard reduction potentials,
2 ClO4- + 12 H+ + 10 e- ----> Cl2 + 6 H2O EoClO4- = 1.47 V
S2O82- + 2 e- ----> 2 SO42- EoS2O82- = 2.01 V
for the system, Ni2+ + Co ---->
Ni + Co2+ Assume T=298 K.
2 AgI + Sn ----> Sn2+ + 2 Ag +
I- has a calculated Eocell
= -0.015 V. What is the value of Kc for this system?
standard cell potential for the reaction
Cu2+(aq) + 2 Ag(s) ----> Cu(s) + 2 Ag+(aq)
is Eocell = -0.46 V. Calculate Kc
for this reaction. Would you expect a relatively large amount of product
for the following reaction, given that its standard cell potential is 0.320
V at 25oC.
+ 2 Cl- + 4 H+ ---> Cl2 + Ni2+
+ 2 H2O
remove the tarnish generated by the reaction of silver with sulphide compounds,
the object can be immersed in a solution of a few grams of table salt (sodium
chloride) and baking soda (sodium bicarbonate) in a litre of water contained
in an aluminum pan. The sulphide tarnish slowly dissolves in the
solution producing Ag1+ ions and S2- ions. Aluminum
metal from the container replaces the silver ions in solution which then
plate back out onto the silver object as neutral silver atoms.
3 Ag+(aq) + Al(s) ----> 2
Ag(s) + Al3+(aq) Eo =
a) Write a balanced half-cell reaction for the reduction of silver ions and calculate its standard reduction potential.
b) Calculate ΔGo for the overall reaction at 25oC.
c) Calculate the cell potential at 25oC if the concentration
of Al3+ and Ag+ ions are each 0.01 M.
for the following reaction.
NiO2 + 2 Cl-
+ 4 H+ ---> Cl2 + Ni2+ + 2 H2O