A Dropping Funnel is a piece of laboratory glassware very useful in transferring liquids. As the name suggests, it is used to drop liquids drop by drop, which is regulated by a stopcock. This is especially required in adding reagents, which is to be added in a controlled manner to an on-going reaction. The controlled dropping of reagents is desirable when quick addition of the reagent may result in side reactions. Dropping funnels generally come with a ground glass joint allowing the funnel to fit squarely onto a round bottom flask. Understandably, it also means that the funnel doesn�t need to be clamped separately.