A Visual Guide to Chemistry Glassware
Glassware in the laboratory comes in a range of different shapes and sizes, and is used for a number of purposes. Don’t know your round-bottomed flask from your Florence flask, or your pipettes from your burettes? This graphic has you covered. Below there’s also a little detail on the usage of each.
These items should be familiar to anyone who’s been in a chemistry practical lesson in school. Test tubes are the archetypal image of chemistry, whilst beakers also make frequent appearances in school practicals. Boiling tubes aren’t that different from test tubes in appearance, but are used when heating is required – they tend to be made of thicker glass, and are slightly larger and wider.
Of all the flasks used in chemistry, the most iconic is the conical (Erlenmeyer) flask. Named after the German chemist Emil Erlenmeyer, who created the flask in 1860, it’s designed so that its contents can be swirled easily without spilling out. This also makes them useful for boiling liquids, and additionally their necks can support filter funnels.
Volumetric flasks are used primarily in the preparation of standard solutions. To create a solution of a specific concentration, we need to know the volume of the solution; the narrow neck of the volumetric flask will have a thin graduation to show where a specific volume is reached.
Round-bottomed flasks and Florence flasks look very similar, but there is a slight difference between the two. Both have round bottoms, designed to spread out heat evenly when they are heated. They are frequently used by chemists for reactions and in rotary evaporators. Whereas round-bottomed flasks will usually have a ground glass joint on their neck, to allow connection to other apparatus, Florence flasks, supposedly named after Florence in Italy, tend to merely have a lip. They can also come with either a flat bottom so they are free-standing, or a rounded bottom, and have longer necks.
The Kjeldahl flask has an even longer neck, and was developed for use in the Kjeldahl method, which is used to determine the nitrogen content in a substance.
Pear-shaped flasks are usually rather small flasks, used for small-scale distillations. Their shape allows recovery of more material than the round-bottomed flasks.
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