Volumetric Analysis notes What is Volumetric Analysis????
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 the flask.
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 the mark.
Hold the stopper firmly -> invert the flask several times and mix
Hold the flask to a light – if you see shimmering waves, mix more.
QUESTION: If during the preparation of the standard sodium oxalate solution, the meniscus in the volumetric flask was overshot by a few drops of water, would the calculated molarity of potassium permanganate be higher or lower than the actual molarity?
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 the flask.
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 the mark.
Hold the stopper firmly -> invert the flask several times and mix
Hold the flask to a light – if you see shimmering waves, mix more.
QUESTION: If during the preparation of the standard sodium oxalate solution, the meniscus in the volumetric flask was overshot by a few drops of water, would the calculated molarity of potassium permanganate be higher or lower than the actual molarity?
