electrolysis Flashcards
why cant sold ionic compounds conduct electricity
the ions are locked and cant move
how can ionic compounds conduct electricity and why
though being melted or dissolved in water
the forces of attraction are broken so ions are free to move and conduct elect
what are ionic compounds that can conduct elec called
electrolytes
what is the negative electrode
cathode
what is the postive electrode
anode
what is the cathode attracted to
protons
what is anode attracted to
electrons
what is high in aluminium oxide
Al2O3
its melting point approx 2000^c
what is Al2O3 mixed with and why
with creolite to lower melting point
reducing energy and energy costs
in Al2O3 what are the electrodes made of
graphite (carbon)
in Al2O3 the ions are..
ions are free to move
what is Al+3 attracted to and the type of reaction
cathode
reduction
what is the half equation for Al+3
Al+3 + 3e- —> Al
what is O2- attracted to and the type of reaction
anode
oxidation
what is O2-‘s half equation
2o2-4e—>o2
why does the anode have to be replaced regularly
the oxygen molecules react with the graphite to form co2 which damages it
why is electrolysis of Al2O3 expensive
melting compounds require lots of energy and lots of energy required to produce electric current
what happens with electrolysis of aqueous solutions and equation
water molecules ionise to form hydrogen ions and hydroxide ions
H2O —-(rvrs) H+ + OH-
what ions are formed with CuSO4 (aq)
Cu2+/H+ and SO4.2-/OH-
what happens when the metal element is more reactive than hydrogen in aq
then hydrogen will be produced at the cathode
what happens when the metal element is less reactive than hydrogen in aq
then the said element is produced at the cathode
for CuSO4 what is used as an inert electrode
platinum
what is produced at the anode for CuSO4
4OH- —-> O2 + 2H2O + 4e-
ox
for CuSO4 what is produced at cathode
Cu2+ + 2e- —> Cu
reduc
what happens if the aq solution contains halide ions
halogen is produced at the anode
