What is dripping funnel?

A dripping funnel is a laboratory apparatus used to add liquid to a reaction vessel or flask slowly and precisely. It consists of a glass funnel with a long stem that is inserted through a rubber stopper into the vessel or flask. The stem has a stopcock or glass valve that can be adjusted to control the flow of liquid. The liquid is added drop by drop, allowing for accurate measurements and precise control over the reaction. Dripping funnels are commonly used in chemistry experiments, particularly in the preparation of sensitive or volatile compounds.