volumetric analysis apparatus. the volumetric flask
TRANSCRIPT
Volumetric Analysis
Apparatus
The Volumetric Flask
Volumetric Flask• Weigh out a specific mass of solute on a
clean, dry clock glass.
• Add the solute to a beaker containing a small volume of water.
• Using a wash bottle wash all traces of the solute from the clock glass into the beaker.
• 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.
• Wash all traces from the beaker, glass rod and funnel into the flask.
• Continue to add deionised water into the flask until the level is just below the mark on the flask.
Volumetric Analysis• Using a dropper fill the
rest of the volumetric flask
until the bottom of the
meniscus is on the mark.
Volumetric Analysis• Stopper the flask and invert about 30 times.
• This ensures the mixture is homogenous.
The Pipette
The Pipette• Rinse with deionised water.
• Rinse with some of the solution it is to contain.
• Use a pipette filler to draw the level
of the liquid to above the mark.
• Allow the liquid to run into a waste beaker until the bottom of the meniscus is on the mark.
• Touch the pipette against the side of a glass beaker. This will remove any droplet of liquid that might be adhering to the pipette.
• Allow the liquid to drain under gravity in to the conical flask.
• Touch the tip of the pipette to the side of the flask but do not blow the last drop out.
The Pipette
The Burette
The 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.
Conical Flask
Conical Flask• Its design allows it to be swirled without the
solution splashing out.
• Before use, wash out with deionised water.
• Do not wash out with the solution it is to contain.
• 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 add to this volume.i.e you have a volume greater than that measured out.