Boiling flask is a kind of flask glassware used in laboratory. It is used to hold liquid substances. It is especially suitable for heating and boiling liquids. It is made of borosilicate glass 3.3. The round-bottomed flask has a circular bottom and a neck on it, which is used to enter and exit the contents or to connect with other experimental vessels. When in use, the bottle neck is fixed on the test stand with a clamp. When using round-bottomed flasks in distillation units, direct heating containers, and metal nets with asbestos or ceramics embedded in the Bunsen lamp can be used to heat them evenly. It can also be used as a container to undertake distillate liquids. Heating can also be done by electric heating pad, water bath, etc. Round-bottomed flasks are often connected to rotary evaporators, and volatile solutions can be removed by decompression heating. Flat-bottomed flasks are mainly used to hold liquid substances and can be slightly heated. Asbestos nets may not be used in heating. Round-bottomed flasks should be used for intense heating. The container is hemispherical, the bottom is flattened for erection, and the upper has a long neck for entry and exit liquid. Stand steadily on the test bench.

The bottom of round-bottomed flask is round, while the bottom of flat-bottomed flask is flat. The round bottom flask should be placed on an iron stand while the flat bottom flask can be placed directly on the test bench.

Bottom: round, flat

Neck: long narrow neck, short wide neck