Electrochemistry Flashcards
What is electrolysis?
The decomposition of a liquid electrolyte using a direct current of electricity.
What is an electrolyte?
The liquid or solution that conducts electricity and is decomposed by it.
What is the negative electrode?
What is attracted to it?
Cathode.
Cations (positive metal ions)
What is the positive electrode?
What is attracted to it?
Anode.
Anions (negative non metal ions)
What material are electrodes made of?
Graphite
What carries the current in the electrolyte?
Ions.
Ions in electrolytes are free to move and carry the charge.
Draw a diagram of the apparatus used in electrolysis.
(Check notes)
Should contain:
Cathode and anode
Crucible
Molton electrolytes
Heat with Bunsen
Lamp
Battery
Pipeclay triangle
Heatproof mat.
What is aluminium ore called?
Bauxite.
Give the equation for the reaction at the cathode during aluminium production.
Al3+ + 3e —> Al
Give the equation for the reaction at the anode during aluminium production.
202- —> O2 + 4e
Why do anodes in aluminium production need to be replaced frequently?
Carbon in graphite reacts with the oxygen produced to form CO2, wearing it away over time.
What is another word for aluminium oxide?
Alumina
Why is cryolite used in the production of aluminium?
A solvent that will reduce the melting point of the alumina from 2000 to 900 degrees Celsius.
Also increases conductivity.
What are the equations at each electrode for the electrolysis of Lead (II) bromide?
Cathode:
Pb2+ + 2e- -> Pb
Anode:
2Br- -> Br2 + 2e-
What are the equations at each electrode for the electrolysis of Lithium Chloride?
Cathode:
Li+ + e- -> Li
Anode:
2Cl- -> Cl2 + 2e-
