I have a formula for a precipitant but don't follow what it exactly means.
"Cooling the concentration solution to room temperature would cause precipitation of the double salt Na7F(PO4)2*19H2O."
What I do not understand is the "*19H2O". What exactly is the meaning of it? Where would all that water be located (evaporated, surrounding molecule)?
If this should be in Undergraduate Chemistry, please move it.
Cheers
Edit: I think I have also noticed when discussing crystallization.