The fuel cell half equations are on the electrochemical series. You just have to be careful whether you're in an acid or alkaline cell
Lead-acid battery:
Anode Pb + SO4 2- -> PbSO4 + 2e-
Cathode PbO2 +4H+ + SO4 2- +4e- -> PbSO4 + 2H2O
Overall: Pb + PbO2 + 2H2SO4 + 2H+ -> 2PbSO4 + 2H2O
You do not need to know these, they will give you at least the half equations, or the full equation and make you derive the other one etc. But because they show up so often, it's nice to know them.
From food chem need to know photosynthesis/respiration, think they're the only specific ones
Also it is a good idea to know equations involving Na2O, Al2O3, SO3
Na2O with an acid: Na2O + 2HCl -> 2NaCl +2H2O
Na2O with water: Na2O + H2O -> 2NaOH
Al2O3 with an acid: Al2O3 + 6HCl -> 2AlCl3 + 3H2O
Al2O3 with base: Al2O3 + 2OH- + 3H2O -> 2Al(OH)4 -
SO3 with base: SO3 + 2NaOH -> Na2SO4 + H2O
SO3 with water: SO3 + H2O -> H2SO4
(don't need to be those exact ones, just need to be able to write an equation if asked for it)
Oh and also from this AoS, the reaction in the sun is 4H -> He + 2e+
Chances are I've probably forgotten something