Electrolysis
Cell
Electrodes
Electrolyte
Anode
Cathode
Types of electrolysis
Can also be a battery
Electrolytic cells
Daniell cell
Chemical energy → Electrical energy
Electrical energy → Chemical energy
Energy needed to drive non-spontaneous redox reactions.
Energy released by spontaneous redox reactions.
Molten compounds
Concentrated aqueous compounds
Dilute aqueous compounds
Uses
Purification
Electroplating
Molten or Aqueous
A process whereby a thin coating of desired material is applied on an object
Protects something from rusting and corrosion and improves its appearances
Place object that you want to be electroplated at position of the cathode
Place plating metal at position of the anode
Electrolyte must be ionic salts containing same metal as plating metal
Impurities fall to bottom of beaker
Cathode gains mass as pure copper is deposited on cathode
Electrolyte will not change colour
Anode sludge
The cations from the anode dissociate into the cathode
Anode loses mass as impure copper discharged
The cations in the solutions are discharged and deposited onto the pure metal
Colour remains constant
Conc. of cations are constant
Daniell cell
uses
battery
electrons alwas go from reactive to less reactive
less reacitvve is anode
more reactive is cathode
the further apart the reactivities of the metals
higher conc of electrongs discharged
larger voltage