Complexation basics

[steven]

Hello,

I am studying concentrated solutions of iron (ii and iii) and sodium chloride solutions. Although I don't formally define any surfaces or surface species (I typically use REACTION to add species to a solution), PHREEQC does predict the formation of iron (iii) chloride complexes such as FeCl2+. Are these only being calculated using mass balances and equilibrium constants, or is a surface complexation model (e.g., dzombak-morel) being employed automatically? Many thanks for any tips!

Best,

Steve

[dlparkhurst]

There is no surface unless you define a SURFACE data block.