DISTILLATION FLASK: CHARACTERISTICS, USES AND RISKS - CHEMISTRY - 2025

The distillation flask, ball flask or distillation flask, is one of the many types of containers made of glass that are used in the laboratory to carry out the distillation process on chemical compounds that are in the liquid phase.

In the same way, its design is based on achieving the best possible separation of the sample to be analyzed, granting a uniform distribution of heat, maximum control of boiling and effective distillation of the liquid.

By Endimion17, from Wikimedia Commons

At the laboratory level, it is commonly necessary to separate mixtures of different substances, either for the purification of the sample or to obtain its different components; so distillation is one of the most widely used methods to achieve this purpose.

Distillation flask features

The material from which distillation flasks are made is a glass made from oxides of boron and silicon, also called borosilicate glass, made as a single piece of glass with no joints or connections.

This glassy material has great resistance to high temperatures and a large number of effects caused by substances of a chemical nature that are the object of the distillation process.

The flask has a spherical-shaped base, which is subjected to direct heating (on a plate or an asbestos grid over a lighter) and must contain the liquid sample, in addition to boiling beads or, failing that, small pieces of porcelain that fulfill the same function.

The spherical base is followed by a “neck”, that is, an open cylindrical area of ​​less width and greater length, through which the distillate vapors rise (at the top of this a rubber stopper is placed, the center of which is crossed by a thermometer).

The last section that completes the structure of the balloon is a gas release tube, which is located perpendicular to the neck, forming a downward angle through which the gaseous substances are evacuated towards a condenser.

Distillation process

Distillation is a technique for separating compounds that are in the form of a liquid mixture, although it is also widely used in the purification of substances that are in this same state of aggregation, eliminating unwanted chemical species.

According to the boiling point or the boiling range, the chemical substances are identifiable and, therefore, separable; so that each substance is stored separately in another container.

In the following figure you can see how the assembly works to carry out a distillation, as well as each of its parts: burner (1), distillation flask (2), connector in case of being a round bottom flask (3), thermometer (4), condenser (5) with its water inlet and outlet holes (6,7), and the collecting container or flask (8).

So the sample is subjected to direct heating over the burner, and upon reaching the boiling temperature it begins to volatilize and rise through the neck of the balloon.

Then, the vapor of the substance with a lower boiling point begins to reach the condenser, pass through it and become a liquid again, to be collected in a container at the end of the journey.

Applications

Distillation of liquid samples

The distillation flask is a glass piece specially designed and used in chemical analysis for the distillation of samples of a liquid nature at the laboratory level.

Separate chemicals

Likewise, this balloon is used mainly for the purpose of separating chemical substances into their components, according to their boiling point or range, obtaining in the first place those with a lower boiling point and, therefore, a greater amount of volatile components..

Although it has been described as an instrument made of glass, it can also be made of a special plastic, depending on its use.

Thanks to its structure, it has greater temperature control when heated, in addition to facilitating the agitation of the sample it contains, eliminating the possibility of spillage.

They can be found in different sizes according to the needs of the analysis, that is, with a capacity of 100 ml, 125 ml, 250 ml…

Applications in biology

On the other hand, it also has biological applications that increase its usefulness, such as the preparation and adaptation of culture broths for microbiology research.

Care and risks

As it is a glass material, great care must be taken when assembling the distillation, as well as with the other components of the same, although the “arm” of the distillation flask is especially fragile when breaking (due to its fineness and length).

Similarly, as it is subjected to heating, care must be taken with burns, as well as always remembering the placement of boiling beads before starting the distillation, because these help to control the temperature and avoid violent boiling.

When the respective plugs are placed on the neck and on the arm of the ball during assembly, they must be placed with the right amount of pressure.

If they are placed too tightly or with great force when pushed, these sections of the flask could break, whereas if they are not placed with enough pressure, the vapors of the substance will escape and the distillation will not be carried out correctly.

In this same sense, the balloon must be well secured to the universal support by means of suitable clamps for its dimensions, to avoid slipping that may lead to possible complications, such as damaging the sample or causing damage to the analyst.

References

1. Wikipedia. (sf). Florence flask. Recovered from en.wikipedia.org
2. ThoughtCo. (sf). How to Set Up Distillation Apparatus. Retrieved from thoughtco.com
3. Sciencing. (sf). What Are the Uses of a Distilling Flask? Recovered from sciencing.com
4. Chang, R. (2007). Chemistry, Ninth edition. Mexico: McGraw-Hill.
5. Krell, E. (1982). Handbook of Laboratory Distillation. Recovered from books.google.co.ve