Sodium sulfate has unusual solubility characteristics in water. Its solubility in water rises more than tenfold between 0 °C to 32.384 °C, where it reaches a maximum of 49.7 g/100 mL.At this point the solubility curve changes slope, and the solubility becomes almost independent of temperature.odium sulfate has unusual solubility characteristics in water. Its solubility in water rises more than tenfold between 0 °C to 32.384 °C, where it reaches a maximum of 49.7 g/100 mL.