I have read that a 1:1 (molar) mixture of sodium sulfate decahydrate and table salt has a melting point of 18 C, while the pure decahydrate has a melting point of 32 C. Does anyone know if having a lower ratio of table salt will cause the melting point to be somewhere in between 18 and 32 C, or if it will just make a mixture of the pure decahydrate and the decahydrate/table salt mixture? I have looked on Google for over an hour, but couldn't find anything. I have also tried to synthesize it from baking soda and Epsom salt (the reaction was listed on Wikipedia), but I couldn't drive the reaction to completion except for boiling, and I don't have the setup for a reflux.