A Glass Beaker is a simple container for stirring, mixing and heating liquids commonly used in many laboratories. Beakers are generally cylindrical in shape, with a flat bottom. Beakers are available in a wide range of sizes, from one millilitre up to several litres.
They may be made of glass (very often borosilicate glass) or of various plastics. Beakers used for holding solutions of corrosive chemicals such as acids or other highly reactive chemicals, are often made of PTFE or other low reactivity materials. Beakers have a cylindrical shape, with flat bottoms so that that they can be set onto many different types of surfaces, and they usually have a thick top (lip) with a spout to make it easier to pour liquids.
Beakers may be covered, perhaps by a watch glass, to prevent contamination or loss of the contents. Beakers are often graduated—marked on the side with lines indicating the volume contained. For instance, a 250 mL beaker might be marked with lines to indicate 50, 100, 150, 200, and 250 mL of volume. The accuracy of these marks can vary from one beaker to another. The standard tall form graduated beaker is sometimes referred to as a Berzelius beaker.
A beaker is distinguished from a flask by having sides which are straight rather than sloping. The exception to this definition is a slightly conical sided beaker is called a Phillips beaker.
