CHM 113 Lecture Notes - Lecture 1: Gravimetric Analysis, Barium Sulfate, Graduated Cylinder
CHM113
Conductimetric Titration & Gravimetric Determination of BaSO4
Introduction
In this experiment, my partner and I analyzed a solution of Ba(OH)2 of unknown concentration by
conductimetric titration and gravimetric determination. Although these methods differ in their
contingent measurements, they both come close to matching the actual literature value of the molarity
of a substance. To Find the concentration by way of conductimetric titration, we used the LoggerPro
apparatus to measure the conductivity in the reaction of sulfuric acid and barium hydroxide. This
analysis is dependent on the total conductance of the solution due to dissolved ions. This method
determined the equivalence point, which is the point at which the number of moles of one substance
completely reacts with the number of moles of another substance, or chemically equivalent quantities
of each substance have been mixed. Gravimetric determination depends on weighing the amount of the
precipitate barium sulfate accurately to determine its mass. For this method of analysis to work, the
compound formed must be pure and of known stoichiometry; the precipitation reaction must be
complete, or almost complete, with at least 99.9% yield; interference by other compounds should be
minimal, so reagents are known and specific compounds; the precipitate should form reasonably large
crystals to be easily filtered; and the molecular weight of the precipitate should be reasonably high.
Procedure
For conductimetric titration…
1) Use a 10mL graduated cylinder to transfer 10.0mL of Ba(OH)2 solution into a 100mL beaker.
With the same graduated cylinder, add 30mL of distilled water to the beaker in 10mL
increments.
2) Connect the Drop Counter to DIG/SONIC 1 of the Vernier computer interface and lower it onto
the ring stand.
3) Connect the Conductivity Sensor to Channel 1 of the interface. Set the selector switch on the
Conductivity Probe to the 0-20000 range. Connect the interface to the computer with the
proper cable.
4) Start the Logger Pro program on your copute. Ope the file Codutieti Dop
from the Advanced Chemistry with Vernier folder.
5) Measure out 60 mL of 0.100 M H2SO4 into a 250 mL beaker. Record the precise H2SO4
concentration.
6) Obtain the plastic 60 mL reagent reservoir. Close both valves by turning the handles to a
horizontal position. Fill the reservoir with water to test for leaks, then empty the water.
7) Rinse the reagent reservoir with a few mL of the 0.100 M H2SO4 solution and pour the H2SO4 into
an empty 250 mL beaker.
8) Using a utility clamp, attach the reservoir to the ring stand. Then fill the reagent reservoir with
slightly more than 60 mL of the 0.100 M H2SO4 solution.
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Document Summary
In this experiment, my partner and i analyzed a solution of ba(oh)2 of unknown concentration by conductimetric titration and gravimetric determination. Although these methods differ in their contingent measurements, they both come close to matching the actual literature value of the molarity of a substance. To find the concentration by way of conductimetric titration, we used the loggerpro apparatus to measure the conductivity in the reaction of sulfuric acid and barium hydroxide. This analysis is dependent on the total conductance of the solution due to dissolved ions. This method determined the equivalence point, which is the point at which the number of moles of one substance completely reacts with the number of moles of another substance, or chemically equivalent quantities of each substance have been mixed. Gravimetric determination depends on weighing the amount of the precipitate barium sulfate accurately to determine its mass.
