Electrolysis

Question 1

When will water react at the cathode?

Answer 1

When the aqueous solution contains cations of more reactive metals (group 1&2 and Al3+)
Or
If acid solutions are electrolysed

Question 2

When will water react at the anode?

Answer 2

If the aqueous solution contains any anions apart from halide ions
Or
If solutions of hydroxides are electrolysed

Question 3

What is the half equation when OH- from water reacts at the anode?

Answer 3

4OH-(aq) —> O2(g) + 2H2O(l) + 4e-

Question 4

Which substances are used to make inert electrodes?

Answer 4

Graphite and platinum

Question 5

When using electrolysis to purify a solution, what materials are the electrodes made out of?

Answer 5

The anode is the impure metal, cathode is pure metal

Question 6

When using electrolysis to purify a solution, what materials are the electrodes made out of?

Answer 6

The anode is the impure metal, cathode is pure metal