ObjectiveThe purpose of this experiment by gravimetric method is to determine the amount of Sulphate in a solution. In addition, to learn to carry out vacuum filtration of Barium Sulphate precipitate and use a desiccator correctly.
TheoryThe amount of Sulphate is determined quantitatively from Barium Sulphate by gravimetric method.
This determination consists of slowly adding, with vigorous stirring a dilute solution of barium chloride to a hot solution of the Sodium Sulphate which is slightly acidified with concentrated hydrochloride acid for the removal of impurities and preventing carbon dioxide in the air from reacting to barium to form barium carbonate precipitate. Dilute and hot solutions with slowly adding and effective stirring are done to decrease the degree of contamination of impurities.
Barium Sulphate precipitate form is allowed to digest which can help to reduce the amount of co precipitation. Co precipitation may result in excess mass hence,
References: .http://chemistry.olivet.edu/classes/chem301/pdf/Gravimetric%20Precipitation.PDF2.http://en.wikipedia.org/wiki/Gravimetric_analysis3.http://kinardf.people.cofc.edu/154L_HONS_HonorsChemistryLaboratory/154_Exp5_GravimetricSulfateAnalysis.pdf4.Analytical Chemistry(5th edition) Gary D. Christian5.http://www.sciencetechnologyaction.com/lessons2.php?studyid=26