Chemistry 12 Worksheet 5.6

CHEMISTRY 12 WORKSHEET 5.6

Electrolysis

1.  If molten CuCl2 is electrolyzed using inert electrodes, what substances will be produced at the anode and the cathode?

2.  An aqueous 1 M solution of NiSO4 was electrolyzed using inert electrodes. What substance was produced at each electrode? What is the minimum voltage that must be applied to the cell?

3.  Predict the overall reactions which you would expect when the following are electrolyzed;

a)  1 M NaI

b)  1 M KCl

c)  1 M CuF2

d)  1M Ni(OH)2

e)  1M K2SO4

f)  1 M Cu(NO3)2

g)  1 M NaOH with Fe electrode

h)  1 M HI with Cu electrode

i)  1 M NiSO4 with Ni electrode

4.  An aqueous solution of CuSO4 was electrolyzed using copper electrodes. The copper anode contained a few percent silver as an impurity.

a)  If 0.55 V is applied to the cell, will the copper in the anode oxidize?

b)  Will the silver oxidize?

c)  If the anode also contains a few percent of lead, will 0.55 V applied to the cell cause the lead to be oxidized?

d)  Which substance will undergo reduction at the cathode?

5.  What voltage must be applied to a 1.0 M solution of HCl to cause any products to form at the electrodes? What products are formed at the anode and cathode?

6.  An aqueous solution of Na2SO4 is electrolyzed. If litmus paper is dipped into the solution around the anode during the electrolysis, what colour will the litmus paper turn? What colour will the litmus turn when dipped in the solution around the cathode? If the electrical current is turned off and the anode and cathode solutions are stirred together, what will be the pH of the resulting solution?

7.  Why can aluminum metal not be produced by electrolysis of aqueous AlCl3?