Question

What passed through the filter paper when the flask was emptied

Answer 1

In this operation, the liquid passes through a porous barrier (sintered glass or filter paper ) and the solid is retained by the barrier.
A: If you don't wet the filter paper with solvent being used in the filtration first, some solid may get under it when the slurry is poured in. ... A: So the solvent comes in contact with all of the solid - use just enough wash to cover the solid, the turn the vacuum on.

Answer 2

hey,

If the flask is empty nothing will pass through the filter paper,

BUT

If that was emptied water from it then water will pass through it and any solid particle present in it will not pass.

Filter paper are used to filter liquid or to separate it in two state