Radiochemical techniques are useful in estimating the solubility product of many compounds. in one experiment, 70.0 ml of 0.030 m agno3 solution containing a silver isotope with a radioactivity of 74,025 counts per min per ml were mixed with 300.0 ml of a 0.080 m naio3 solution. the mixed solution was diluted to 700.0 ml and filtered to remove all of the agio3 precipitate. the remaining solution was found to have a radioactivity of 44.4 counts per min per ml.