CHEMISTRY 12 – ELECTROCHEMICAL CELLS WORKSHEET
1) For the following electrochemical cells, label the parts of the cell (1 mark), write the equations for
the individual half-reactions (2 marks) and overall reaction (1 mark), indicate the directions in
which the ions and electrons move (2 marks), determine which electrode gains and loses mass (2
marks) and calculate the E° (1 mark).
a)
b)
c)
d)
e)
f)
2) Calculate the E° for the following redox reactions and predict whether the reaction is spontaneous or
not under standard conditions. (4 marks)
(a) 2 Cr + 3 Cu2+ → 2 Cr3+ + 3 Cu
(c) 2 Fe2+ + MnO2 + 4 H+ → 2 Fe3+ + Mn2+ + 2 H2O
(b) Ni2+ + 2 Ag → 2 Ag+ + Ni
(d) Sn4+ + 2 Cl- → Sn2+ + Cl2
3) Which material could be used as the cathode to produce an E° = +0.46 V? (1 mark)
4) Draw and label the parts of an operating electrochemical cell using a zinc anode that will produce an
electric current having a voltage of 1.56 V at standard conditions. (4 marks)
5) Calculate the E° for the following electrochemical cell. What happens to the pH at each electrode
and the [Ag+] as the cell operates? What is the E° at equilibrium? (3 marks)
6) Consider the following:
2 Cr2+ + Tl3+ → 2 Cr3+ + Tl+
E° = +1.19 V
Identify the standard potential for the half-cell reaction: (1 mark)
Tl+ → Tl3+ + 2 e7) Consider the following redox reactions:
2 Ag+ + Cd → 2 Ag + Cd2+
E° = 1.20 V
2+
3+
3 Cd + 2 Nb → 2 Nb + 3 Cd E° = 0.70 V
What is the E° for Nb3+ + 3 e- → Nb? (1 mark)
8) Ethanol, C2H5OH, is oxidized by an acidified dichromate solution according to the following
equation:
2 Cr2O72- + 16 H+ + 3 C2H5OH → 4 Cr3+ + 11 H2O + 3 CH3COOH
The E° for the reaction above is +2.98 V. Calculate the E° for the oxidation of ethanol. (1 mark)