What Kinds of Solutions Are Beakers Used For?

Beakers are useful vessels in a wide variety of lab experiments.

Beakers are simple cylindrical containers made from borosilicate glass. Typically the bottom is flat and the top has a low lip, together with a small spout to help you pour out the contents. Beakers can be used to hold solutions during an experiment. These simple vessels enjoy a wide variety of uses.

Aqueous Solutions

A solute in water is called an aqueous solution. Glass beakers can hold aqueous solutions --- salts, acids and bases, for example. The beaker contains the reactants so they can be mixed or brought into contact. Since borosilicate glass is much less likely to crack when heated, the beaker can also be used to heat a solution over a Bunsen burner or on a hot plate. Aqueous solutions of chemicals that can react with glass should not be held in beakers. Hydrofluoric acid, for example, reacts with glass and requires special handling.

Non-Aqueous Solutions

Solutions of chemicals dissolved in solvents other than water can also be held in beakers. A solution of salts dissolved in ethanol, for example, can be held in a beaker. A beaker has a wide open mouth, however, so volatile solvents (compounds that evaporate easily) should either be kept in a different kind of glassware or handled under a hood, especially if they are potentially toxic or dangerous. Tetrachloromethane, for example, is a useful solvent but also a probable carcinogen, so a solution of this chemical should only be handled under a fume hood.

Waste

Sometimes when you are working at your lab bench, you may need a temporary repository to store waste before transporting it to the appropriate hazardous waste container (if applicable) or to the sink for disposal. A beaker can store nonvolatile waste solutions of this kind. It's important not to mix different kinds of waste, however, if they have the potential to react violently together. If you mix sodium cyanide and hydrochloric acid, for example, you could generate hydrogen cyanide gas, which is extremely poisonous.

Analyte

A beaker could be used to contain the analyte for a titration. In this kind of procedure, you drip a chemical called a titrant into a vessel like a beaker or an Erlenmeyer flask. Using the volume of titrant needed to neutralize the solute in the analyte, you can calculate the concentration of the original solution. Generally, a "tall-form" beaker with tall sides should be used for this kind of procedure, since the drops of titrant falling into the analyte can cause it to spatter or splash. If spattering remains a concern, an Erlenmeyer flask can be used instead.

References

• Illustrated Guide to Home Chemistry Experiments: Beakers
• Oxford University Chemistry: Safety Data for Carbon Tetrachloride
• "Chemistry 7L Laboratory Manual"; Sandrine Berniolles; 2011