Question

What is expansion/ sublimation/contraction/ diffusion/physical change/ random motion

Answer 1

This process is very helpful in separating a volatile solid from a non - volatile solid.the powdered substance is taken in a China dish and covered with a perforated filter paper ans an inverted funnel.the dish is carefully heated on a sand bath.
The vapours passing through the holes in the paper condense on the inner sides of the funnel. The non - volatile impurities remain in the dish.