A burette with a glass stopcock is laboratory glassware used for measuring and dispensing precise volumes of liquids. The burette is a long, cylindrical piece of laboratory glassware with a graduation scale used for measuring the volume of liquid. The glass stopcock is a valve located at the bottom of the burette that controls the flow of liquid.

It allows for precise dispensing of the liquid, ensuring that the correct amount is delivered. The burette with a glass stopcock is commonly used in chemical and biological experiments where precise liquid measurements are required, such as titration, which involves adding a reagent to a solution until a reaction is complete.

The burette and glass stopcock are typically made of durable, chemically-resistant glass, and the glass stopcock can be easily adjusted for accurate and consistent flow control.