The PTFE flask usually has the appearance of a round belly and a thin neck, which is obviously different from the beaker. Its narrow mouth is used to prevent the solution from splashing out or reduce the evaporation of the solution, and can be used together with the rubber stopper to connect other PTFE equipment. When the solution needs a long time of reaction or heating and reflux, the polytetrafluoroethylene flask is generally used as the container. The opening of the flask has no projecting gap like a beaker, so it is easier for the solution to flow down the outer wall when pouring, so the tetrafluoroethylene stirring rod is usually used to gently touch the mouth of the flask to prevent the solution from flowing down the outer wall. Because the mouth of the flask is very narrow, it is not suitable for mixing with a tetrafluoroethylene stirring rod. If mixing is needed, you can hold the mouth of the flask and turn your wrist slightly to smooth mixing. When heating and refluxing, put a magnetic stirrer in the bottle to heat the stirrer for stirring. Flasks can be divided into flat bottom flasks and round bottom flasks according to their different appearances
