Electrolysis of Copper Sulfate

Question 1

What is the chemical symbol for copper sulfate?

Answer 1

CuSO4

Question 2

What four ions does copper sulfate contain?

Answer 2

Cu 2+
SO4 2-
H+
OH-

Question 3

What happens when you electrolyse copper sulfate solution with inert electrodes?

Answer 3

• Copper is less reactive than hydrogen, so copper metal is produced at the cathode (you see a coating of copper on the electrode).
• There aren’t any halide ions present so oxygen and water are produced at the anode (you see bubbles of oxygen gas forming).

Question 4

What are the half equations for what happens when you electrolyse copper sulfate?

Answer 4

At the cathode:
Cu 2+ + 2e- → Cu

At the anode:
4OH- → O2 + 2H2O + 4e-

Question 5

What are the electrodes made of in copper sulfate electrolysis?

Answer 5

Copper electrodes are used, instead of inert electrodes.

Question 6

What is the solution used in copper sulfate electrolysis?

Answer 6

Copper sulfate solution.

Question 7

What happens to the masses of the anode and the cathode, during the electrolysis of copper sulfate?

Answer 7

The mass of the anode will decrease and the mass of the cathode will increase.

Question 8

Why does the mass of the anode decrease, and the mass of the cathode increase?

Answer 8

Because copper is transferred from the anode to the cathode.

Question 9

How can you increase the rate of electrolysis?

Answer 9

Increase the current.

Question 10

What does the electrical supply act by?

Answer 10

Pulling off copper atoms at the anode, and offering electrons at the cathode to nearby Cu 2+ ions.