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Chemistry 213 Sample Quiz Chapter 20-1
Name:_________________________________________
1.
How many electrons are transferred in the following reaction? _________________
2MnO4- (aq) + 6H+ (aq) + 5ClO3- (aq)
a)
b)
c)
d)
e)
2.
2
4
6
8
10
A galvanic cell is set up with copper and aluminum electrodes in contact with aqueous solutions of
Cu2+and Al3+, respectively, at 25oC. The standard reduction potentials are:
Cu2+(aq) + 2eAl3+(aq) + 3e-
a)
 2Mn2+ (aq) + 3H2O (l) + 5ClO4- (aq)
 Cu(s)
 Al(s)
Eo = 0.34 V
Eo = -1.66 V
Calculate the potential of the cell, Ecello, in volts at the standard state where Cu2+and Al3+ are each 1.00
M.
b) The electrons flow from _____________________ to ______________________ in this cell.
c)
__________________ is oxidized at the anode and ______________________ is reduced at the
cathode.
d) Write a balanced chemical equation for the overall reaction.
e)
The number of electrons transferred in the overall reaction is ________________.
f)
Give a line notation for this galvanic cell.
g) The cell reaction has operated long enough for the [Al3+] to have changed to 1.40 M and [Cu2+] to
0.400 M. Do you expect the cell potential to be higher or lower than Ecello calculated in (2-a)? Explain
your reasoning.
h) Calculate the new cell potential in (2-g).