Chapter 13 - Volumetric Analysis (Equipment)

How to weigh solute

Weigh out a specific mass of solute on a clean, dry clock glass.​

Where to add the solute

Add the solute to a beaker ​

containing a small volume of water.​

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What to use when washing out solute

wash bottle

What to stir the mixture with

Stir the mixture with a clean glass rod.​

Volumetric Flask​

Using a funnel transfer the contents ​

of the beaker into a clean ​

dry volumetric flask.​

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Wash all traces from the beaker, glass rod and funnel into the flask.​

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Continue to add deionised water into the flask until the level is just below the mark on the flask.​

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How to make sure mixture is homigenous

Stopper the flask and invert about 30 times.​

​This ensures the mixture is homogenous.​

he Pipette

1.Rinse with deionised water.​

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2.Rinse with some of the solution it is to contain.​

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3.Use a pipette filler to draw the level ​

of the liquid to above the mark.​

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4.Allow the liquid to run into a waste beaker until the bottom of the meniscus is on the mark.​

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The Pipette​

Touch the pipette against the side of a glass beaker. This will remove any droplet of liquid that might be adhering to the pipette.​

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Allow the liquid to drain under gravity in to the conical flask.​

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Touch the tip of the pipette to the side of the flask but do not blow the last drop out.​

Burette

Rinse with deionised water.​

Rinse with some of the solution it is to contain.​

Use a small funnel when ​

filling the burette.​

The burette is filled almost to the top and then the tap is opened to fill the part below the tap.​

Re-fill the burette until the bottom of the meniscus is on the mark.​

Connical flask

Its design allows it to be swirled without the solution splashing out.​

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Before use, wash out with deionised water.​

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Do not wash out with the solution it is to contain.​

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It will be holding an exact volume of a solution and so if it was washed prior to this it would have droplets that would affect this volume.​