Question

Which property of a filter paper is used to separate an insoluble solid from a liquid?

Answer 1

Filter paper has small pores on it which allow only liquid (and materials soluble in liquid) to penetrate.

Filter paper don't allow the insoluble solid to penetrate from it and hence the insoluble solid and liquid gets separated

Answer 2

Filter paper has small pores on it which allow liquid to pass through it.
Filter paper don't allow the insoluble solid to pass