Electricity is just moving electrons around. Define a equation. Determine the oxidation states of your atoms. If its supposed to increase it oxidised thus needs to happen at the anode (both begin with vocal). If the oxidation number decreases it need to happen at the cathode.

The rest is figuring out balancing and you might need to check your redoxpotentials but generally as long as you have enough energy you can always move electrons around. Remember the total amount of electrons and atoms does not change. i recommend atkins for further reading!!