Electrolysis Flashcards
what is a redox reaction
a reaction where both oxidation and reduction occurs
in terms of electrons what’s oxidation and reduction
oxidation- loss of electrons
reduction - gain of electrons
explain in terms of gain or loss of electrons which species has been oxidised and which species has been reduced when magnesium reacts with hydrochloric acid
magnesium-oxidised (Mg to Mg2+)
hydrogen in HCL- reduced (H+ to H2)
what is electrolysis
using electricity to separate an ionic compound into its elements in molten or in solution .ions are discharged (they loos/gain electrons)
what is an electrolyte
The ionic compound being separated by electrolysis. The liquid which conducts electricity
what is a cathode and anode?
cathode- negative electrode
anode - positive electrode
what occurs at the cathode and anode during electrolysis
reduction occurs at the cathode
oxidation occurs at the anode
opposites attract
in aqueous electrolysis, which elements is discharged at the cathode? oxygen is produced at the anode unless what?
less reactive element discharges at the cathode. Hydrogen is produced if the metal is more reactive than hydrogen
Oxygen is produced at the anode unless the solution contains a halide ion then the halogen will be produced
how is aluminium manufactured? why is it expensive?
aluminium is made through the electrolysis of aluminium oxide and cryolite
lots of energy is need to produce the current, which makes it expensive
why is cryolite used in manufacturing of aluminium?
lowers the melting point of aluminium oxide, reducing energy cost
what’s the half equation of aqueous solution Na2SO4
2H+ 2e- —> H2 (Cathode)
4OH- —> 2H20 + O2 +4e- (anode)
what’s the half equation of molten and aqueous KCL
molten:
K+ + e- —> K (cathode)
2Cl- —-> Cl2 +2e- (anode)
aqueous:
2H+ +2e- —->H2 (cathode)
2Cl- —->Cl2 +2e- (anode)
what are the half equations of the aqueous Cu Br2?
Cu2+ + 2e- —>Cu (cathode)
2br- —>Br2 + 2e- (anode)
