9. Take the pipet out of the liquid and wipe off the outside of the pipet.

10. Place the tip of the pipet into a new container, release the pressure from your

finger, and allow the liquid to flow down the wall of the container.

11. You will notice that there is a small amount of liquid remaining in the tip of

the pipet. Leave that small amount of liquid in the pipet. The small amount of

liquid is supposed to be there as the pipets

are designed as TD (to deliver) pipets and

calibrated knowing that the small amount

of liquid gets left behind.

Volumetric Flasks

Volumetric pipets are designed to deliver a

specific volume, whereas volumetric flasks

are designed to contain a specific volume.

Like volumetric pipets, volumetric flasks are

designed for only one specific volume, so if

you want a different volume, then you need

to use a different volumetric flask.

When filling a volumetric flask, you need to

be careful when the liquid approaches the

line because you will need to start completely

over once it passes the line. It is helpful to

use a dropper to control the last bit of liquid

added to ensure that it is not filled above the

line.

29

Figure 3.9: Volumetric Flask: "File:Brand

volumetric flask 100ml.jpg"

by Lucasbosch is licensed under CC BY-SA

3.0.