Electrolysis. Flashcards
What is Electroylsis?
Splitting something up using electricity.
What is an electrolyte?
An ionic compound that is split up.
What is an anode?
Positive electrode
What is a cathode?
Negative electrode
What is an anion?
A negative ion
What is a cation?
A positive ion
what is P.A.N.I.C?
Positive Anode, Negative Is Cathode
What happens at the anode?
Negative charged (anions) move to the anode. Oxidation.
What happens at the cathode?
Positively charged ions (cations) move to the cathode. Reduction.
Why can’t ionic compounds conduct electricity?
A solid has a fixed lattice that cannot move, electrons must move to carry a charge therefore electricity can not be carried out.
In aluminium extraction, why does a mixture of aluminium oxide + cyrolite used?
It lowers the melting point.
Why does the positive electrode have to be replaced at regular intervals in aluminium extraction?
Graphite reacts with oxygen to form carbon dioxide, so they gradually burn away.
Why is aluminium expensive?
Extracting is expensive.
How do we extract metals that are more reactive than carbon?
Electrolysis.
What is a halogen?
Group 7.
What is Electrolysis in an aqueous solution?
When an aqueous solution is electrolysed, the most reactive ions stay in the solution while the less reactive ions are discharged when they go to the desired electrode.
What happens at the cathode in electrolysis of an aqueous solution?
Hydrogen will be produced if the metal is more reactive than hydrogen, e.g. if the metal was potassium, hydrogen would be produced, if the metal was copper, copper would be produced.
What happens at the anode in electrolysis of an aqueous solution?
if the solution contains a halogen, that halogen would be produced, if not oxygen is produced.
How do we show reactions at the electrodes?
With Half equations.
What is produced in electrolysis of brine?
Hydrogen, Chlorine and Sodium Hydroxide.
