A distillation flask, also known as a still flask or a boiling flask, is a type of laboratory flask used in distillation, a process for separating and purifying liquids. It is typically made of borosilicate glass and has a round or flat bottom, a narrow neck, and a large volume to accommodate the distillation mixture.

The flask’s shape and size allow for efficient heating and boiling of the mixture, and the narrow neck helps to minimize spillage and control the release of vapors. Distillation flasks are commonly used in combination with a condenser, which helps to cool and condense the distilled vapors, and a receiving flask, which collects the purified liquid.

The distillation process involves heating the mixture in the distillation flask until the desired component vaporizes and condenses in the condenser. The purified liquid is then collected in the receiving flask. Distillation flasks are widely used in a variety of applications, including the purification of liquids, the separation of mixtures, and the preparation of solutions.