What is electrolysis?
Electrolysis is the process of splitting up ionic compounds using electricity
What is an electrolyte?
An electrolyte is a compound in its liquid state or in solution
a) What is an electrode?
b) What is a cathode?
c) What is an anode?
a) Electrodes conduct electricity to the electrolyte
b) A cathode is a negatively charged electrode
c) An anode is a positively charged electrode
a) What are anions and cations?
b) Which are usually non-metals and which are usually metals?
a)Anions are negatively charged ions that are attracted to the anode. Cations are positively charged ions that are attracted to the cathode.
b)Anions are usually non-metals and cations are usually metals.
Why should inert electrodes be used in electrolysis?
So that the electrodes don't react with the electrolyte.
Why is electrolysis only performed on solutions or liquids and not on solids?
Because the electricity required for electrolysis can't conduct through solids as the ions cannot move for the salt to conduct. However, the ions can move and therefore conduct in a liquid state or a solution.
Why may hydrogen be released from the electrolyte during electrolysis?
When the electrolyte is in an aqueous form, if the metal is more reactive than hydrogen the solution finds it easier to discharge the positively charged hydrogen at the cathode than the more reactive positively charged metal, which instead reacts with the water. However, this will not happen to a molten electrolyte as there is no hydrogen present in the electrolyte.
Why is electrolysis an important industrial process?
Because it is a way of extracting metals and purification.
What would you get at the cathode and anode if a sodium sulphate solution was electrolysed?
Cathode - Hydrogen as it is positively charged and more easy to discharge than the more reactive sodium.
Anode - Oxygen as it is negatively charged and we cannot get SO4 on its own.
What groups are halides and halogens from?
Halides are from group 1 and halogens are from group 7.
During the electrolysis of copper sulphate solution with carbon electrodes what would you expect to see at the cathode and anode?
Cathode - Would go brown.
Anode - Fizzling.
What happens to the positive and negative ions of the electrolyte during electrolysis?
Positive ions gain electrons at the cathode and become atoms. Negative ions lose electrons at the cathode and become atoms. They are discharged.
What is electroplating?
A type of electrolysis that uses noninert electrodes to coat the cathode in a metal.
For electroplating what is the anode, what is the cathode and what is the electrolyte?
The cathode is the object you want to coat, the anode is a piece of metal you want to coat the object with and the electrolyte is a solution containing ions of the coating metal.
How can you purify a metal using electrolysis such as copper?
If you electrolyse a solution with ions of the metal, in this case, copper sulphate with an impure copper anode and a pure copper cathode, the impurities will be released into the solution from the anode and pure copper will be deposited at the cathode.
What happens in terms of mass at the anode and cathode in purification through electrolysis?
Anode - Will lose mass and impurities are lost.
Cathode - Will gain mass as the pure metal will be deposited.