When performing vacuum filtration of a solid in an unknown solvent, is it necessary to go and find out the solvent composition, so that some fresh solvent can be used to wash the filtrate with?

2 answers

The unknown solid should not have too high a solubility in the wash liquid. The idea is to dissolve and remove impurities without losing the unknown solid with the wash. The safest choice of wash liquid is the same liquid in which the solid formed.
Okay I guess the only solution is to find out what the solvent is and then make a mixture out of that.

Thank you,
GK