1. utilizes electrical energy to create chemical energy
Electrolytic Cells
utilizes electrical energy
to create chemical energy

2. Electrolytic Cells
electricity used to force non-spontaneous reactions to occur
endothermic
electrolytic cells identified by presence of battery or power supply

3. galvanic/Voltaic cell
chemical
potential
energy
electrical
potential
energy
electrolytic cell

4. Electrolytic Decomposition of H2O
H2 produced at one electrode, O2 at other
2H2O + energy 2H2 + O2
Can you tell from the picture the side where H2 is produced?
Where O2 is produced?

5. electrolytic cell works in reverse of a
galvanic cell
this time:
Zn is cathode; where reduced takes place
&
Cu is anode; where oxidation takes place

6. two types of electrolytic cells
1. Fused Salt Cells – used to purify metals
(fused means melted!)
2. Electroplating Cells – designed to cover a surface with metal so will have specific properties

8. Electroplating
move desired coating from anode onto object to be plated
solution contains ions of element to be plated
- in this case Cu+2

9. Can Cu be plated onto Al? Al above Cu in Table J
reaction will not happen spontaneously so…
external energy source (power supply or battery) needed to force reaction to occur

10. An Ox ate a Red Cat anode: electrode at which oxidation occurs
cathode: electrode at which reduction occurs
electrode polarity opposite than galvanic cell!
anode is POSITIVE
cathode is NEGATIVE

11. A POX on Electrolytic Cells
Anode – Positive – Oxidation
electrolytic cell: polarity determined by outside power supply
anode is attached to (+) terminal
cathode is attached to (-) terminal

12. (+) (-) (+) (-) Battery anode: where oxidation happens Cu  Cu+2 + 2e-
cathode: obj being plated
- where reduction happens
Cu e-  Cu
Cu(s)
Cu+2
SO4-2
Note: just moving Cu around

14. Plating cathode: object to be plated
anode: made of metal want to plate on object
solution: contains ions of plating metal
Plating

15. purify metals from their ores Fused Salt Cells: used to
Why does NaCl have to be molten?
To which electrode will Na+1 ions be attracted to?
To which electrode
will Cl-1 ions be
attracted to?
ox: 2Cl-1  Cl2 + 2e-
red: Na+1 + 1e-  Na