Electrolysis Flashcards
Revision
What is Electrolysis?
Electrolysis is a chemical process of separation by using electricity to split up ionic compounds
What is an Electrolyte?
An electrolyte is a molten/dissolved ionic compound.
Why does the compound need to be in solution/molten?
When an ionic substance is dissolved in solution or molten, the ionic lattice is broken down allowing the ions to move freely
PANIC
Positive
Anode
Negative
Is
Cathode
Faraday’s Law of Electrolysis states that…
Mass of a substance deposited at an electrode is directly proportional to the amount of charge passed through it.
What ore is aluminium oxide found in?
Bauxite
What is cryolite and why is it used?
Cryolite is an aluminium based compound with a lower melting point than aluminium oxide and is used to lower it’s melting point
Name the diatomic molecules
Have Hydrogen
No Nitrogen
Fear Fluorine
Of Oxygen
Ice Iodine
Cold Chlorine
Beer Bromine
Why must the anode be replaced regularly?
Oxygen molecules produced at the anode react with the graphite (carbon), and degrade over time, forming carbon dioxide gas.
Why is electrolysis expensive?
- Melting compounds require a lot of energy
- Large amounts of energy are required to produce the electric current
In electrolysis of Aqueous solutions, at the cathode…
- Hydrogen (gas) is produced at the cathode if the metal is more reactive than Hydrogen
- A solid layer of the pure metal will coat the cathode if the metal is less reactive than Hydrogen
In Electrolysis of Aqueous solutions, at the anode…
- If the aqueous solution contains Halide ions, then the halogen will be produced at the anode
- If no halides are present then OH- ions will be discharged and oxygen (gas) and water will be formed.
