???????? 6 - Pressure equalising funnel

Used when liquids have to be introduced into vessels under vacuum. Also known as a dropping funnel which is a type of laboratory glassware used to transfer fluids. They are fitted with a stopcock which allows the flow to be controlled. Dropping funnels are useful for adding reagents slowly, i.e. drop-wise. This may be desirable when the quick addition of the reagent may result in side reactions, or if the reaction is too vigorous