(Use the data from Turner et al. for all complexes except carbonate - see below) lg1(Ce(CO3)+)=5.33lg2(Ce(CO3)2)=9.24lg1(Eu(CO3)+)=5.75lg2(Eu(CO3)2)=10.11 Based on these calculations, estimate peq for the Ce(IV)/Ce (III) and Eu(III)/Eu(II) couples. You will need to estimate the lg for Eu2+ and for Ce4+ (likely by analogy with other similar ions). Consequently, what oxidation state do you expect to be stable for these elements in seawater at 25C that is saturated with air at a pH of 8.2 ? There is some evidence in marine systems that Ce(IV) and Eu(II) are the stable forms under particular conditions. What conditions are these, and what is the "evidence