I have a problem with a sample made from $\ce{CaCl2*2H2O}$ and $\ce{MgSO4*7H2O}$ in about equal amounts. I took the two salts, pressed them together, and the result was a weird brine that was very wet and almost seemed to turn into water before my eyes.
I am wondering what happened here, and was hoping that someone could walk me through it. As you can tell by the title, I believe that a reaction might be involved that I did not consider when making the sample.
As far as I know, the two salts are both very hygroscopic, so it could be that they simply adsorbed water and that is why the sample became wet. However, the effect seemed more severe after mixing them together, so I am thinking that a reaction might have been involved.
Could it be that the two salts reacted this way? $$ \ce{CaCl2*2H2O + MgSO4*7H2O -> CaSO4*2H2O + MgCl2*6H2O + H2O} $$ And if so, what happens with the leftover water that is not bound? Especially since $\ce{MgCl2*6H2O}$ is even more hygroscopic than any of the other salts, could it be that the water was attracted by the $\ce{MgCl2*6H2O}$, which then turned the sample into a brine?
I'm just trying to understand what happened, I did not add any heat, but I did add a lot of pressure.