Separating solids from liquids – filtration

If a substance does not dissolve in a solvent, we say that it is insoluble. For example, sand does not dissolve in water – it is insoluble.

Filtration is a method for separating an insoluble solid from a liquid. When a mixture of sand and water is filtered:

  • the sand stays behind in the filter paper (it becomes the residue)
  • the water passes through the filter paper (it becomes the filtrate)

The slideshow shows how filtration works:

Shows a beaker with a mixture of solid and liquid in it. Another beaker has a funnel with some filter paper in

A beaker containing a mixture of insoluble solid and liquid. There is filter paper in a filter funnel above another beaker.