Solubility of solid AgClxBr1-x solution was studed in the sea water wi
th salitity 0.5-35 parts per thousand. At 35 parts per thousand the st
ability phase is AgCl0.56Br0.44 and total Ag+ activity coefficient is
1.26 x 10(-5). It is in a good agreement with thermodynamical calculat
ions of total activity coefficient 1.78 x 10(-5). In the seawater with
35 parts per thousand salinity two species Ag:AgCl2- (46.9%) and AgCl
32- (47.7%) dominate.