Description

An Erlenmeyer flask (or Erlenm) is a flat-bottomed container with a conical shape. The top of the container (or neck) is more or less narrow depending on the model. An Erlenmeyer flask is usually made of glass (in which case it can be heated), but it can be found in plastic.

The graduations on an Erlenmeyer flask are indicative – they are not at all precise. They serve only to give an indication of the volume poured into the Erlenm, or the volume remaining in it.

Erlenmeyer flasks come in a variety of sizes (typically 5 mL to 2 L): choose a size that is appropriate for the volume of liquid to be poured into the flask. Likewise, there are several neck widths; here again, the choice depends on the desired use. The narrower the neck, the less liquid will be spilled.

Uses

An Erlenmeyer flask is typically used to:

• mix solutions or liquid products (manually or with the help of a magnetic stir bar)
• collect a solution of interest (e.g. extract from a separatory funnel or preparative chromatographic column)
• store and preserve a liquid solution (for a short period of time: a few hours to a few days, if necessary in a refrigerator)
• contain a solution in order to carry out a dosage directly in the Erlenmeyer, such as a titration (see the sheet on "How to perform a titration")

Thanks to its narrow neck and the absence of a spout, an Erlenmeyer flask can be closed: either by covering it with parafilm, or with a stopper (plastic or cork). In practice, only Erlenmeyer flasks with a taper outer joint can be sealed with a ground glass stopper.