Electrolysis Flashcards
1
Q
What does electrolysis mean?
A
- Splitting up with energy
2
Q
What is the process of electrolysis?
A
- Current passes through electrolyte.
- Ions move to electrodes
- Positive move to cathode (-ve), gain + reduction
- Negative move to anode (+ve), lose + oxidised
- Creat flow of charge
- Uncharged elements form + discharged from electrolyte
3
Q
Why do electrolytes need to be dissolved or molten?
A
- So that ions are free to move
4
Q
Why can’t ionic solids be electrolysed?
A
- Fixed position, ions can’t move
5
Q
Where will the elements be discharged in the electrolysis of molten lead bromide?
A
- Lead: Cathode
- Bromine: Anode
6
Q
Why is it hard to extract a highly reactive metal?
A
- Too expensive
- Require a lot of energy to melt
7
Q
Why is aluminium oxide mixed with cyolite?
A
- To lower the boiling point
8
Q
Why is a mixture used as the electrolyte?
A
- Contains free ions, will conduct electricity
9
Q
Why does the positive must be continuously be replaced?
A
- Made of carbon, it reacts with oxygen to form carbon dioxide
10
Q
What forms at the negative electrode?
A
- Metals
11
Q
What forms at the positive electrode?
A
- Non-metals
