Purification

Question 1

4 things to be included

Answer 1

1. Set up
   - anode:
   - cathode:
   - electrolyte:
2. Relevant half equations
3. Electrode reactions
   - ref to E value
   - full arrow
4. Impurities
   - more reactive than copper;
   - less reactive than copper

Question 2

After writing down relevant equ, the explanation?

Answer 2

By controlling the voltage, the current runs through the circuit, impurities more reactive than copper are readily oxidised at anode;

Hence, ________ are oxidised

Question 3

After reactions at anode?

Answer 3

Impurities less reactive than copper are oxidised at anode but collect below anode as sludge

Question 4

Description at cathode?

Answer 4

Pure copper

All (+) metallic cations will be attracted to cathode;

but bcos E value for Cu2+ is the most positive;

It will be reduced back to copper

Question 5

Reaction at cathode?

Answer 5

Cu2+ + 2e- -> Cu(s)

________ remained in sol;

Overall charge is the transfer of pure copper from the anode to the cathode