Solubility in the System (NH₄)₂S₂O₈—NH₃—H₂O and Mean Activity Coefficients of Saturated Solutions of (NH₄)₂S₂O₈

The solubility data of ammonium peroxodisulfate in aqueous ammonia solutions at 15.5 °C have been evaluated using the relative activity coefficient expansion. Using the known value of the mean activity coefficient of saturated solution of ammonium peroxodisulfate in pure water, values of the mean activity coefficients of this salt in the saturated solutions of the given system have been calculated.