Molten Electrolysis Flashcards
What is electrolysis?
The breaking down of a compound using electricity. The substance to be broken down is connected into a circuit with a cell or battery.
What are electrodes?
They connect the substance into the circuit.
What is the positive electrode called?
The anode.
What is the negative electrode called?
The cathodes.
What 2 things must the material on electrode be?
-Able to conduct electricity
-Inert (unreactive)
What 2 materials can an electrode be made from and are they cheap or expensive?
-Graphite (cheap)
-Platinum (expensive)
What is the electrolyte?
The substance to be broken down.
What are the only compounds that conduct electricity in electrolysis?
Ionic compounds conduct electricity when they are molten or dissolved as the ions are free to move.
Why won’t solid ionic compounds work in electrolysis?
Because the ions can’t move.
Why won’t covalent compounds work in electrolysis?
Because the molecules aren’t even charged.
what is attracted to the cathode?
Cations - positive anions
what is attracted to the anode?
Anions - negative ions
What happens at the anode?
Non-metal ions lose electrons to form molecules.
Write the half equations for the electrolysis of molten magnesium chloride (MgCl2)
At the anode:
2Cl- -> Cl2 + 2e-
At the cathode:
Mg2+ + 2e- -> Mg
What happens at the cathode?
Metal ions gain electrons to form atoms.
