Electroylsis/aluminium oxide

Why can’t solid ionic compounds conduct electricity

As the ions are locked in place and are not free to move

What happens when an ionic compound is melted or dissolved in water

The forces of attraction are broken and the ions are free to move with a liquid or solution. So these liquids and solutions can conduct electricity

What are electrolytes

Liquids or Solutions that can conduct electricity

What is the negative electrode called

Cathode

What is the positive electrode called

Anode

When you pass an electric current through electrolytes

causes the ions to move to the electrodes.

Describe what happens to the ions with molten lead and bromine

The pb2+ ions of lead move to the cathode as opposite charges attract gaining 2 electrons to from pb atoms(reduction)

pb2+ + 2e→Pb

The Br- ions move to the anode losing one electron to from Br atoms(oxidation)

2Br→ Br2 + 2e-

What electrode does metals and non-metals move to

Positive Metals move to cathode

Negative Non-metals move to anode

When do we extract metals by Electroylsis

When the metal is too reactive to be reduced or react with carbon

Where is aluminium extracted from

Aluminium is extracted from the compound aluminium oxide by electrolysis

What does aluminium oxide contain

Aluminium ion(AI3+)

Oxide ion(O2-

Describe the stages of Electroylsis of aluminium oxide

1)Aluminium oxide is mixed with cryolite to lower melting point as aluminium has a very high melting point. This also reduces the amount of energy needed and saves money

2)Apply an electric current to the molten aluminium oxide

3)The cathode and graphite are made out of graphite(carbon) as it’s a good conductor of electricity and has a high melting point

4)The ions are free to move so the molten mixture will conduct electricity

5)The AI3+ ions are attracted to cathode to gain three electrons to form an aluminium atom AI3+ + 3e→AI

6)The O2- ions are attracted to anode to lose 2 electrons to from a oxygen atom 2O2→O2 + 4e-

Why must anode be replaced regularly

As the oxygen molecules produced at the anode react with the graphite(carbon) forming carbon dioxide gas

Why is electrolysis expensive

As melting the compounds such as aluminium oxide requires a great deal of energy

A lot of energy is required to produce the electric current