Electrolysis

Question 1

What is electrolysis

Answer 1

A process used to separate chemicals using electricity

Question 2

Explain the process of electrolysis

Answer 2

Ionic substance is melted or molten
Two rods are placed in the solution and a current is passed through them
The ions then move to oppositely charged rods
Separating the substances

Question 3

Why must electrolysis occur when the sample is dissolved or molten

Answer 3

They are ions so are free to move around

Question 4

Which ions are attracted to which plate

Answer 4

Cations ( positive ions) attracted to cathode (negative plate)
Anions (negative ions) attracted to anode (positive plate)

Question 5

The rods are inert. What does inert mean?

Answer 5

Unreactive
Won’t react with the chemicals

Question 6

Explains what happens at the cathode

Answer 6

Positive ions are attracted to it and move towards it
When they hit the cathode they gain electrons
Positive ions are reduced at the cathode

Question 7

Explains what happens at the anode

Answer 7

Negative ions are attracted to the positive plate so move towards it
When they hot the anode they lose electrons
Negative ions are oxidised at the anode

Question 8

When is electrolysis used to extract metals form their ores

Answer 8

When the metal is too reactive to be reduced by carbon

Question 9

Explain the extraction of aluminium from its ore( bauxite) using electrolysis

Answer 9

Bauxite has a very high melting point so it is mixed with cryolite reducing it melting point
Once molten bauxite is electrolysed using graphite rods
Positive Al3+ ions move towards the negative plate and is reduced forming Al which is heavy so sinks to the bottom where it is collected
Negative O2- ions move towards the positive electrode where it is oxidised to form O2 gas, O2- ions can also react with the carbon in graphite to form CO2