5.5 - Electrolysis Flashcards
What is electrolysis?
breaking down of a compound using electricity
What is the positive electrode called?
anode
What is the negative electrode called?
cathode
What must the electrodes be made of?
-a conductive solid
-inert (reactive)
What is the electrolyte?
the substance to be broken down
What are the positive ions called and what electrode are they attracted to?
-cations
-attracted to cathode
What are the negative ions called and what electrode are they attracted to?
-anions
-attracted to anode
What happens at the anode? M
non-metal ions lose electrons to form molecules
What are the observations of magnesium chloride at the anode? M
bubbles of pale green gas
What happens at the cathode? M
metal ions gain electrons to form atoms
What are the observations of magnesium chloride at the cathode? M
grey solid formed
Water molecules dissociate to form…
H+ and OH- ions
What forms at the anode if a halide ion is present? M
halogen element
What forms at the anode if a halide ion isn’t present? M
oxygen and water
What forms at the cathode if the metal is less reactive than hydrogen?
metal element
What forms at the cathode if the metal is more reactive than hydrogen?
hydrogen produced
