Beaker Glass and Erlenmeyer Flask

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In any lab glassware must be on this, the beaker glass and Erlenmeyer flask. Both of them have a scale but cannot be used to measure liquids accurately, only estimates. Beakers are commonly made of glass (today usually borosilicate glass), but can also be in metal (such as stainless steel or aluminium) or certain plastics (notably polythene, polypropylene, PTFE). A common use for polypropylene beakers is gamma spectral analysis of liquid and solid samples. Beaker made of glass can be used for a variety of liquids and solids, while the beaker plastic or metal only for liquids or solids that have a neutral, such as saline or distilled water, this is done to prevent unwanted reactions between acids or bases with a beaker of plastic or metal.

Beaker has a variety of sizes, among which 50 mL, 100 mL, 200 mL, 250 mL, 500 mL, 1000 mL and so on. For instance, a 250 mL beaker might be marked with lines to indicate 50, 100, 150, 200, and 250 mL of volume. These marks are not intended for obtaining a precise measurement of volume, but rather an estimation. Most beakers are accurate to within 10%. Beaker used for various purposes, such as making the solution both of liquids and solids, weighing solids, as a container to hold the solution, even as a temporary waste container. Beaker does not have a lid. The tools used to seal glass beaker namely watches. Watch glass is a glass circle like a plate which at its center curved downward. At the top of the beaker there is a mouth like a teapot to facilitate fluid out of the beaker.

How to use the beaker as a container for weighing is sure beaker clean, had been washed with soap and scrubbed using a brush tube. Dry the beaker using a tissue. After it was placed on top of a dry watch glass, this is done to prevent other substances into the beaker during and after the weighing process. As the container to create a solution that is open beaker containing solids and closed the watch glass, pour distilled water or other solvents into the beaker until all solids submerged, then stirring using a stirring rod, stirring time try not to make a sound that is too noisy. The sound caused by friction stir bar in the beaker.

After all solids dissolved, add distilled water or other solvents to the extent desired. Beaker used as a container for storing temporary solution, or as a temporary waste container must be kept closed to prevent other substances into the beaker. And give the label on the beaker if necessary, to prevent the exchanged solution. To take a solution or make a solution of solids that will be damaged if exposed to light, the beaker can be wrapped with black carbon paper. But now there are tools included brown glass beaker for this solution or solids.

Other glassware in general at the lab is Erlenmeyer flask. Erlenmeyer flask made of glass, shaped like a pipe, but getting to the top, the diameter is getting smaller. At the top there is no mouth teapot like on beakers and do not have a cover. It is named after the German chemist Emil Erlenmeyer (1825–1909), who created it in 1860. Erlenmeyer most widely used in the titration process. This is because when Erlenmeyer shaken by hand, or splashing out a solution opportunity is very small as the diameter of the top of the Erlenmeyer more smaller than the diameter of the bottom.

And Erlenmeyer flask has a comfortable neck to grip by hand. At the time of titration, Erlenmeyer has shaken with one hand, and rocked in a direction that is clockwise or vice versa. This is done to stir the solution in Erlenmeyer with the reagent from the burette. In addition, magnetic stirrer can be used for stirring. Insert magnet into Erlenmeyer flask and place it in a magnetic stirrer and then turn them on. Magnet Erlenmeyer will spin and the solution will be mixed. In addition to rotating, magnetic stirrer can also heat the solution up to a certain temperature. Erlenmeyer shake pace was not too fast and not too slow. Thus the solution in Erlenmeyer is mixed perfectly.

Erlenmeyer has a wide range of sizes among which 100 mL, 250 mL, 500 mL, 1000 mL and so on. For instance, a 5000 mL beaker might be marked with lines to indicate 100, 200, 300, 400, and 500 mL of volume. These marks are not intended for obtaining a precise measurement of volume, but rather an estimation. There are 2 types Erlenmeyer, which is transparent and brown. Erlenmeyer brown used for the solution that is easily damaged by light. Erlenmeyer also be used to prepare a solution which must be heated, when the water bubbles that arise because of the heat, it will be splattered against the wall and back again to Erlenmeyer bottom, this prevents the solution splashing out Erlenmeyer.

Erlenmeyer flasks are also used in microbiology for the preparation of microbial cultures. Plastic or glass Erlenmeyer flasks used in cell culture are sterilized and may feature vented closures to enhance gas exchange during incubation and shaking. The use of minimal liquid volumes, typically no more than one fifth of the total flask volume, and baffles molded into the flask's internal surface both serve to maximize gas transfer and promote chaotic mixing when the flasks are orbitally shaken. The oxygen transfer rate in Erlenmeyer flasks depends on the agitation speed, the liquid volume, and the shake-flask design. The shaking frequency has the most significant impact on oxygen transfer.

Oxygenation and mixing of liquid cultures further depend on rotation of the liquid "in-phase", meaning the synchronous movement of the liquid with the shaker table. Under certain conditions the shaking process leads to a breakdown of liquid motion – called "out-of-phase phenomenon". This phenomenon has been intensively characterized for shake flask bioreactors. Out-of-phase conditions are associated with a strong decrease in mixing performance, oxygen transfer, and power input. Main factor for out-of-phase operation is the viscosity of the culture medium, but also the vessel diameter, low filling levels and/or a high number of baffles.