Question

why must the filter paper in filtration be moistened before using?

Answer 1

The filter paper is a semi-permeable paper barrier placed perpendicular to a liquid or air flow.

It is used to separate fine substances from liquids or air. It is used in science labs to remove solids from liquids.

The filter paper is moistened so that is stick to the funnel which doesn't let the air pass through the passage, which increases the speed of filtration.