phase diagram of NaCl-water?

Question

I am studying the phse diagram of NaCl-water using Differential scanning colorimetry. I often find that the system supercools and thus distorts my results. Any idea of how to avoid supercooling of NaCl-water system. The conc ranges i tried are below eutectic (5 wt%, 10 wt% and 20 wt%)

thanks for the suggestion. But could you suggest some suitable chemical which can be added to avoid supercooling yet at the same time not interfere with te DSC? I have done the experiment at higher scan rates but there is significant error in the data. what to do?

Answer 1

You've probably already tried cooling slowly, to give time for the crystalization to start. Maybe there is something you can add to the solution that would induce the crystalization to happen at the correct temperature, but wouldn't mess up the thermal behavior. Maybe small crystals of something insoluble, but that had a lattice close enough to NaCl that it could grow on it easily. If all else fails, sometimes you can do extrapolations from the distorted DSC's and approximate where the crystalization would have started if it was behaving itself.