CBSE Class 9 Answered
Filter paper is folded in the following steps:
1. The round piece of filter paper is taken and folded in half.
2. This half folded paper is folded again.
3. The twice folded filter paper is opened to form a hollow cone and can now be used for the process of filtration.
Filtration is used for separating insoluble substances from a liquid. The mixture is poured into a filter paper cone fixed in a funnel by using a glass rod as guided. The liquid passes through the filter paper which has millions of tiny holes in it. The solid particles (being bigger in size) do not pass through the filter paper and remain behind on the filter paper. It is called as residue. The clear liquid obtained is called filtrate.