ERLENMEYER FLASK

 APPEARANCE

An Erlenmeyer, commonly known as a conical or E-spot, 

 is a widely used type of laboratory flask which features a flat,

conical body,

and a cylindrical neck.

It is named after the German chemist Emil Erlenmeyer, who created it in 1861.

The Erlenmeyer is usually marked on the side (graduated)

to indicate the approximate volume of contents, 

and has a spot of ground glass or enamel where it can be labeled with a pencil. 

It differs from the beaker in its tapered body and narrow neck.

The opening usually has slight rounded lips 

so that the Erlenmeyer can be easily stoppered using a piece of cotton wool. 

Alternatively, 

the neck may be fitted with a female ground glass joint to accept a glass stopper.

The conical shape allows the contents to be swirled or stirred during an experiment, 

either by hand or by a shaker; 

the narrow neck keeps the contents from spilling out. 

The small neck reduces evaporative losses compared to a beaker,

while the flat bottom of the conical flask makes it unlikely to tip over and spill.

HOW TO USE IT

Conical flask used in a Titration setup.

Erlenmeyers are used in chemistry labs for titration, especially of pH.

Erlenmeyer flasks are often used to heat liquids,

e.g. with a Bunsen burner.

For that purpose,

the flask is usually placed on a ring held to a ring stand by means of a ring clamp.

A wire gauze mesh or pad is usually placed between the ring and the flask to prevent the flames from directly touching the glass.

An alternative way to set up the apparatus is to hold the flask by the neck with a test tube clamp fixed to the stand.

If the flask is to be heated in an oil or water bath,

a 'C' shaped lead or iron weight may be placed over the conical part of the flask to prevent it from floating in the bath.

Erlenmeyers are also used in microbiology for the preparation of microbial cultures.

Plastic Erlenmeyer flasks used in cell culture are pre-sterilized

and feature closures and vented closures to enhance gas exchange during incubation and shaking.