CHEM 121 Lecture Notes - Volumetric Flask, Sodium Oxalate, Purified Water
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Lab 4B - Volumetric Analysis notes
What is Volumetric Analysis????
VA is the quantitative analysis based on measuring volumes
The most common kind = a titration
A standard solution of unknown concentration is chemically reacted with an unknown
concentration in order to determine the concentration of the unknown.
Measurements must have at least 4 sig figs
Preparation of a standard solution
Weigh the sample on an analytical balance by differences into a beaker.
Dissolve with a small volume of water or another solvent
Sodium Oxalate is best done with 25 mL 3M sulfuric acid and 75 mL water
Hotplate @ 2 will help. Make sure the solid is dissolved before you do anything.
Rinse the 250.0 mL volumetric flask and funnel with de-ionized water to clean the glassware
Quantitatively transfer the solution into the flask – rinse the beaker and funnel and stirring rod
with de-ionized water into the flask to ensure that allthe dissolved fluid sample is transferred to
Rinse the beaker several times with de-ionized water.
Fill the flask with H2O to a few cm below the 250.0 mL mark – don’t go over.
Using a dropper, carefully add de-ionized water until the bottom of the meniscus is in line with
Hold the stopper firmly -> invert the flask several times and mix
Hold the flask to a light – if you see shimmering waves, mix more.
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