C6 - Electrolysis 1️⃣✅

Question 1

What is the electrolyte?

Answer 1

The liquid solution containing the dissolved ionic compound - ions have to be capable of moving freely for it to be considered an electrolyte

Question 2

What are the electrodes?

Answer 2

Metal or carbon solid conductors that the electrons can flow through

Question 3

What is the positive electrode called?

Answer 3

Anode

Question 4

What is the negative electrode called?

Answer 4

Cathode

Question 5

What does electrolysis do?

Answer 5

Using electricity to convert ions in an ionic compound back into its pure elemental form by the transferring of electrons

Question 6

How does electrolysis work?

Answer 6

1. Using a battery current is passed through electrolyte
2. The -ve ions are attracted to the anode and become discharged (go from charged ion to neutral atom) due to oxidation (loss of e-)
3. +ve ions are attracted to the cathode and also become discharged due to the electrons from the anode travelling through the wire to the cathode where they are transferred to +ve ions to firstly oxidise them (gain e-) and make them stable/ discharge them as well to make them also neutral atoms

Question 7

Why can’t we initially use electrolysis to separate metal oxides?

Answer 7

Because they are solid so their ions are fixed in place so cannot move around freely, a necessary part of electrolysis

Question 8

How are metal oxides extracted via electrolysis?

Answer 8

1. Metal oxides are purified/ collected from their ores
2. They are then mixed with cryolite to lower their melting point
3. They are then melted into molten liquids so that there ions can move freely
4. Same thing occurs -ve 02 ions would go to anode and undergo oxidation and loose electrons to become neutral/ discharged (single oxygen atoms will combine to make 02 molocule)
5. +ve metal ions would go to cathode and undergo reduction and recieve e- from the anode (from oxgen) to discharge them adn also make them neutral/ pure substances
6. Pure molten metal then sinks to bottom of beaker and can be collected for use

Question 9

In the extraction of what metal is cryolite used and what does it do?

Answer 9

Used in the extraction of aluminium to lower the temperature of the aluminium oxide so less energy is required to melt it

Question 10

Mnemonic for the anode and cathode charges

Answer 10

PANIC
P ositive
A node
N egative
I s
C athode