A conical flask, also known as an Erlenmeyer flask, is a type of laboratory glassware commonly used for mixing, storing and heating liquids. It has a conical shape with a flat bottom, a cylindrical neck and a tapered opening. The 250ml conical flask has a volume capacity of 250.

The flat bottom of the flask allows it to stand on a flat surface, while the tapered opening enables the user to attach a rubber stopper or a glass funnel for filtration or aeration. The cylindrical neck of the flask is wider than the opening, which helps to prevent spills while pouring liquids.

Conical flasks are typically made of borosilicate glass, which is resistant to thermal shock and can withstand high temperatures. The glass is also transparent, allowing the user to observe the liquid inside the flask.

The 250ml conical flask is a medium-sized flask that is commonly used in chemistry labs for experiments that require the handling of relatively small volumes of liquid. It is also used in industrial settings for mixing and storing liquids.