Solubility of MgSO47H2O in water

[sbrothy]

I was naively under the impression that all these data was available on the Material Safety Data Sheet for the compound in question. As in a search like “msds MgSO47H2O”…

 

[JT Smith]

Me too.

But that MSDS doesn't contain enough information to determine the solubility at 10°C in g/g H2O. It also says that epsom salt is hygroscopic without any elaboration.

One of the websites I came across was this one where someone explains how they grow crystals of various salts as a hobby. It actually looks kind of fun. Maybe I will grow a big epsom salt crystal now. :-)

 

[sbrothy]

No, one of the weaknesses of the MSDSs are that they don't all contain the same info. It depends on who printed them and for what use they were intended. Sorry.

 

[Mayhem]

Don't use SDS and similar date for solubility. They can be wildly inaccurate.

A reaxys search shows that the solubility of the heptahydrate to be 29.77 wt% at 35 C. (E. L. Simons, 1951: https://doi.org/10.1021/ja01153a087)

I indexed a Russian journal stating 27.47 wt% at 25 C, but I cannot access the article directly.

 

[JT Smith]

Thank you for that. Those values are consistent with the data from Millipore Sigma that I included in the graph above.

I believe I'm finished with determining epsom salt solubility. The bigger problem of pottery glaze chemistry and all the variables of application and firing are much more complicated and often not entirely solvable. I think sometimes I gravitate towards less important but more tractable problems as an escape.