Tammy Broccas September 15, 2019
volumetric flask

A volumetric flask is a piece of laboratory glassware mainly used to accurately measure specific quantities of liquids at a particular temperature.

It is mostly used in chemistry. A volumetric flask is much more precise when compared with beakers or Erlenmeyer flasks.

It is normally pear-shaped with a flat bottom. They are available in classes A and B where class A is recognized in being the highest in accuracy.

It is used in analytical chemistry for the preparation of the solutions. It is either made of glass or plastic and it is usually fitted with a stopper which is made from a chemically resistant plastic such as polypropylene other than glass.

Its long neck has a single ring graduation mark and a label. The label is meant to show the nominal volume, tolerance, calibration temperature, class, relevant, manufacturing standard, and the manufacturing logo.

A volumetric flask is basically characterized by having a bulb and a long neck. Although there are some with rounded bottoms, most volumetric flasks have a flattened bottom which enables them to be set onto a lab bench.

A volumetric flask should be calibrated before use so as to avoid introduction of systematic errors into the measurements and also reduce the random error inherent while using the instrument.

It is important to fill the volumetric flask twice the solution that you are about to fill with. Put the stopper on the opening and shake the flask.

This is important so that all the surface area inside the flask is covered. When you do this, you are sure that the solution will not be contaminated or diluted when you pour it on the volumetric flask.

Could you be wondering when it is the most appropriate time to use a plastic volumetric flask as opposed to glass flask?

Well, the plastic is much needed if you need to trace analysis on analysts at ppb levels that might be lost by adsorption on the glass surface.

How to use a volumetric flask

Since there are different sizes of volumetric flasks, begin by selecting the most appropriate size for your procedure. Next, measure and add the solute for the solution.

Add enough solvent to dissolve the solute. Keep adding the solvent until you get near the line marked on the volumetric flask. Fill the flask using a pipette. Ensure all liquid drain down from the sides of the flask…

Leave a comment.

Your email address will not be published. Required fields are marked*

Pin It on Pinterest

Share This