Volumetric flask, what is it and how to choose it well?

November 2, 2021

Also known as a Volumetric Flask , the Volumetric Flask is a laboratory instrument used for medication and determining the accuracy of the volume between liquids. This, like other laboratory instruments, is very popular in the field of science since it manages to give a precision of its measurement.

History and creator of the Volumetric Flask

Like the Erlenmeyer flask , the inventor of this instrument is Emil Erlenmeyer . He himself was born in 1985 and died in 1909, however he is still remembered for his great contributions to science. In this particular case, his invention of the Volumetric Flask is considered one of the most important achievements for both chemistry and physics.

Specifically, we can say that this laboratory material was discovered in 1861, after different theories studied in 1883 were carried out. Some of them were those of Guanidine or the study of compound with lactone in 1880.

The idea of ​​this flask was to work as a calculator to accurately give the volume of different liquids. Something that was very important in both like physics and chemistry back then. However, with the passage of time it began to become an important instrument for mixing solutions.

In this way, this instrument began to be used for other purposes such as ensuring the mix for later use. It is important to note that they have a lid or stopper that works to seal the mixture. In this way, prevent the composition from being contaminated or altered by any external agent.

What is a Volumetric Flask?

In simple terms, we define a Volumetric or Volumetric Flask as a glass container that is usually used to prepare solutions and also to measure the volume of liquids. Its application is mainly in chemistry and physics laboratories, where many of these procedures are carried out.

It is known to have a flat bottom with a narrow and elongated neck, which has a mark known as gauging . This mark serves to indicate the liquid capacity that the flask must and can contain. This is important since it guarantees and makes it easier to give an accurate measurement of the liquid, with various variations.

Volumetric Flask Features

At first glance we can see that this container is pear-shaped , with a flattened base. In the same way we can notice other characteristics such as;

  • It has a plastic , cork or tempered glass stopper, which is usually made of polypropylene. As we can imagine, its function is to cover the flask, all to avoid that the sample does not drain.
  • It has an information label on the neck , which has a series of basic instructions about this appliance. For example, we can find information such as the volumetric capacity, the temperature it supports and the manufacturer’s brand.
  • Long and thin neck , which has several marks that allow to determine the volume of the liquids.
  • It has a mark known as capacity and at the mouth of it we can find considerable distances. These distances allow us to shake the content if necessary.
  • It comes fully calibrated to hold a specified volume of liquid at a specified temperature.

Volumetric Flask Types

In this case we find two types of volumetric or volumetric flask. The first is classified as class A and the second as class B. When it comes to the class A volumetric flask we have that it is used in Analytical Chemistry . In general, it is used to study the chemical composition of a sample or some material.

Moving on to class B, we have that these are less accurate when it comes to making a volumetric measurement . Besides, there is the fact that the glass with which they are made is of lower quality. Due to all this, class B volumetric flasks are used for the preparation of solutions.

Uses of the Volumetric Flask

As with other types of flask, this one in particular has certain specific uses such as;

Measure the volume of liquids

If there is one thing these types of flasks are used for, it is for measuring the volume of liquids. This is completely understandable, as it contains a series of markings on the neck that serve just this purpose.

When the Volumetric Flask is used to measure the volume of a certain liquid, we can find that it curves up or down . At the same time we will see how the edges look higher and the center will be at a much lower level or vice versa.

What happens in these cases is a phenomenon known as ” meniscus “, the curvature of the same can vary depending on the type of liquid to be treated. It is important to mention that in this phenomenon what must be taken into account to make the measurement is the central point.

How to use it to measure the volume of a liquid?

To begin we must know that the fact that this laboratory material has such a narrow neck. Which allows to considerably facilitate the medication . With this in mind and knowing what the “meniscus” phenomenon is, we are almost ready to use this instrument.

The last thing we need to know is that to measure the volume of the liquid . We must bear in mind that the eye must be at the level of the capacity. It can’t be too high or too low, it must be right at this point. At the same time we must perceive the capacity as a straight line, in order to find the exact measure.

Prepare solutions

Another use that can be given to the Volumetric Flask is for the preparation of solutions. In particular case, it is commonly used for the preparation of standard solutions . The latter are the ones in which the amount of solute and solvent to be mixed is known.

How to use the Volumetric Flask to prepare solutions?

To use it in this type of work, we must measure the volume of the solvent in the volumetric flask. In relation to the solute, it must be measured on a precision balance or analytical balance. After having done this, we must place the cap and shake the mixture to achieve the integration of the materials.

Methodology of use of the Volumetric Flask

Now that we understand the uses of this laboratory instrument, we must know how to use them. To begin we must deeply clean the flask and then dry it. This step is important, as it prevents any residue on the tool from altering the volume of the substance or the solution that we want to prepare.

We must bear in mind that this instrument only works at a minimum of 20 ° C and a maximum of 25 ° C. Keep in mind that these were specifically designed to work at those temperatures.

With this in mind and once the flask is clean, we must add the solute, which must be previously weighed. In case the solute ends up adhering to the neck of the flask it is important that we remove it using the solvent carefully. To avoid this type of problem, it is best to make the solute go directly to the bottom.

Once we have added half the solvent, we must proceed to shake the flask and thus dissolve the solute. It is important to be careful when we are going to do it, otherwise we can spill the mixture. At the same time, we must prevent it from coming into contact with the capacity.

After this we must finish adding the solvent, until we achieve the indicated mark. Finally we must place the cap and shake , with a little more force to make the mixture more homogeneous.

How to care for the Volumetric Flask?

The Volumetric Flask, like other materials used in laboratories, requires care. Keep in mind that if you do not receive the correct care, the precision of this can be affected.

On the other hand, it is important to avoid high temperatures . Keep in mind that the glass in this can end up altering. When this occurs, the accuracy of measuring volumes can be seriously impaired. In this sense, avoiding overheating is important.

On the other hand, it is important not to wash the flask using a brush , as its interior may be affected. This is important as it can ruin your accurate volumetric medication ability.

In this sense, for maintenance it is important to wash the flask using distilled water , and a solvent to rinse. To all this it is important to add that the volumetric figure given by this laboratory material is very accurate. However, it is not always necessary to use it in a correct way to obtain the results that are as close to reality as possible.

Finally, we must add that under no circumstances should we directly pour or dilute a sample directly up to the marked line without stopping. Be aware that this can cause the volume of the mix to change. Because of this it is important when we are going to use it, we slowly pour the instruments.

Dr. Loony Davis5
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Born and raised in Brussels in an English family, I have always lived in a multicultural environment. After several work experiences in marketing and communication, I came to Smart Water Magazine, which I describe as the most exciting challenge of my career.
I am a person with great restlessness and curiosity to learn, discover what I do not know, as well as reinvent myself daily, someone who is curious about life and wants to know. I enjoy sharing knowledge.
This is my personal project but I also collaborate in other blogs, it is the case, the most important web on water currently exists in the US, if you are interested you can read my articles here.

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