Changes at the electrodes

Question 1

What happens when ions reach an electrode?

Answer 1

1) Negatively charged ions lose electrons to become neutral atoms.
2) Positively charged ions gain electrons to become neutral atoms.

Question 2

What is reduction?

Answer 2

Reduction is gaining electrons.

Question 3

What is oxidation?

Answer 3

Losing electrons.

Question 4

What is the rule to work out what will happen when doing electrolysis in solutions?

Answer 4

If two elements can be produced at an electrode, the less reactive element will usually be formed. In aqueous solutions there will usually be positively charged metal ions, as well as H+ ions, that are attracted to the cathode.

Question 5

What happens at the anode in the electrolysis of aqueous solutions?

Answer 5

Hydroxide ions, from water are often discharged, you see oxygen gas given off at the anode.

Question 6

What is the order of discharge at the anode? (starting with the easiest)

Answer 6

Halide ion > hydroxide > all other negatively charged ions.