Electrolysis Flashcards
Why do ionic compounds do no conduct electricity when they are solid?
ions are in fixed positions in their giant lattice
positively charged ions move to the …
negative electrode (cathode)
negatively charged ions move to the…
anode
what are electrodes made of?
-carbon or graphite
Why are electrodes made out of carbon/graphite?
good conductor of electricity so electrodes do not react with the electrolyte
reduction
gaining electrons
oxidation
losing electrons
What is produced at the cathode in an aqueous solution:
if the metal is more reactive, hydrogen is produced
What is produced at the anode in an aqueous solution:
oxygen gas
halogen is produced (halide)
What ore does aluminium oxide come from?
bauxite ore
Why is aluminium oxide mixed with cryolite?
- lower melting point, reducing the energy needed to extract aluminium
Does aluminium oxide have a very high melting point
yes
Why are carbon anodes replaced?
they gradually burn away as the oxygen reacts with the carbon anodes forming carbon dioxide gas
define inert
unreactive substance
describe the set-up of an electrolysis experiment:
- 2 electrode are placed in an electrolyte with a gap between them
- one is connected to the positive terminal of the power supply
- the other is connected to the negative terminal of the power supply
