MAGNESIUM SULFATE ASSOCIATION AT 25C IN SYNTHETIC SEAWATER1

Abstract

The formation of magnesium sulfate ion pairs, Mg 2+ + SO 4 2− ⇌ MgSO 4 0 , in an aqueous NaCl‐MgCl 2 ‐Na 2 SO 4 solution was characterized by a stoichiometric association constant, K* mGso 4 = [MgSO 4 0 ]/[Mg 2+ ] [SO 4 2− ]. A value of K* mGso 4 = 10.2 was obtained at 25C and at an ionic strength of 0.670 by a potentiometric procedure. This value was used to make a preliminary estimate of the sulfate speciation in seawater.