[milky9311]

Here's the question

"Determine the upper limit for the reduction potential for each of the Ti(IV) / Ti(III) couple and the Ti(III) / Ti(II) couple.

E°(H2O / H2) = –0.42V, E°(O2 / H2O) = 0.82V"

I don't know how to go about starting to answer

Thanks in advance