It is a three neck flask of which two side necks are parallel. It is manufactured from heat resistant boro-silicate glass.It comes with glass cocks which are constant pressure retention device. Flask outer diameter also varies according to its size.It comes in various capacities according to the requirement.It is used as a Laboratory glassware mostly for chemical and biochemical work.Its sizes are usually inscribed on glass. The ends of the necks are usually conical ground glass joints. They are standardized. Because of the round bottom, cork rings are needed to keep the round bottom flasks upright. When in use, round-bottom flasks are commonly held at the neck by clamps on a stand.they allow more uniform heating and boiling of liquid.
These flasks are often used to contain chemical reactions run by chemists, especially for reflux set-ups and laboratory-scale synthesis. Boiling chips are added in these distilling flasks for distillations or boiling chemical reactions to allow a nucleation site for gradual boiling. This nucleation avoids a sudden boiling surge where the contents may overflow from the boiling flask. Stirring bars or other stirring devices suited for these round-bottom flasks are sometimes used.For a reflux set-up, a condenser is typically attached to the middle or only neck of the flask being used. Additional necks on a flask could allow a thermometer or a mechanical stirrer to be inserted into the flask contents.
