C6 Flashcards
What is the electrolyte?
The compound that is broken down in electrolysis.
What are the two electrodes?
The positive electrode is the anode and the negative electrode is the cathode.
Which ions go where and what happens?
The negative ions go to the anode and the positive ions go to the cathode, they lose their charge and become elements.
What is cryolite?
It is a catalyst used to lower the melting and boiling temperatures of a substance.
How are the two ways something can be electrolysed and why?
Either being molten or in a solution due to the charge being able to move.
What are the rules for half equations for electrolysis?
Hydrogen would form at the cathode when the metal is more reactive than it, and at the anode if there is a halide ion present that is discharged, but if not hydroxide ions are discharged.
What do the half equations look like?
2H+(aq)+2e-=H2(g)
4OH-(aq)=2H2O(l)+O2(g)+4e-
What are the uses of electrolysis?
Pans, overhead power cables, aeroplanes, cooking foil, drink cans, window and patio door frames, bicycle frames and car bodies.
What is bauxite?
The ore of aluminium which is electrolysed in extraction of aluminium, and it is mixed with cryolite to reduce the melting point.
Why does the anode need to be replaced?
This is due to the carbon anode reacting with the oxygen formed, making carbon dioxide.
What are the half equations of aluminium electrolysis?
Al3+(l)+3e-=Al(l)
2O2-(l)=O2(g)+4e-
What is the electrolysis of brine?
You get chlorine gas an hydrogen gas at the anode and cathode and you get sodium hydroxide left in the solution.
