C4: ELECTROLYSIS

Question 1

What is electrolysis?

Answer 1

a method of separating +ve and -ve ions using electricity (works on ionic compounds that are molten/in aqueous solution

Question 2

Which electrode are +vely charged ions attracted to?

Answer 2

the -ve electrode/the cathode

Question 3

Which electrode are -vely charged ions attracted to?

Answer 3

the +ve electrode/the anode

Question 4

Half equation for magnesium

Answer 4

Mg^2+ +2e^- –> Mg

Question 5

Half equation for fluorine

Answer 5

2F^- –> F2 + 2e^-

Question 6

Half equation for oxygen

Answer 6

2O^2- –> O2 + 4e^-

Question 7

What ions are found in aqueous solutions?

Answer 7

H^+ and OH^- ions

Question 8

What is the rule at the anode (+ve electrode) for electrolysis of aqueous solutions?

Answer 8

-if a group 7 ion is present, the group 7 element forms at the anode
-otherwise OH moves to the anode and O2 is produced

Question 9

What is the rule at the cathode (-ve electrode) for electrolysis of aqueous solutions?

Answer 9

-if the metal is less reactive than hydrogen, the metal is produced
-otherwise hydrogen is produced