ES3 (Electrolysis) Flashcards
what is the co product
produced along with the wanted product in main reaction
what is the by product
produced by unwanted side reaction
what is the cathode
negative electrode, attracts cations
what is the anode
positive electrode, attracts anions
what are cations and anions
positive and negative ions
what process happens at the cathode
reduction
what process happens at the anode
oxidation
what happens at the cathode
if the metal ion is more reactive than hydrogen, water is reduced. if it is less reactive, the metal is formed.
what happens at the anode
if there is a halogen present, it is oxidised. if not, water is oxidised instead.
what is the equation for oxidation of water
2H20 = O2 + 4e- + 4H+
what is the equation of reduction of water
2H20 + 2e- = H2 + 2OH-
what is the product at the cathode and anode
cathode - metal
anode - non-metal, apart from hydrogen
what happens when the anode and metal ions in the solution are the same
the anode loses mass as the atoms change to ions and go into the solution
