The laboratory aid that is used to transfer liquid from a wide-mouth container to a small-mouth container is the funnel. It is shaped like an inverted cone, with an extension of a small tube where the liquid passes. The filter paper is shaped into a cone and inserted to the funnel. The funnel allows you to transfer the liquid without spilling. In filtration, you separate the solid precipitate from the liquid filtrate. It depends on you which one of these you would keep. If you want to keep the filtrate, then the funnel is an efficient way to use if you don't want any of the filtrate to go to waste.
