Gravimetric analysis is a quantitative method for determining the amount of an analyte in a sample. This is done by transforming the analyte into a water insoluble form, which then precipitates out of the solution and can be isolated by filtration. Lastly, the mass is obtained so the number of moles and percentage of the sulfate in the precipitate can be determined. In this lab, a sample with a sulfate is measured and dissolved in hydrochloric acid. The sulfate is isolated with barium chloride and then heated to form larger particles and to purify the precipitate. The precipitate is then collected by filtration and it’s mass it taken. The amount of sulfate in the original sample can be calculated from the mass of the precipitate.
To use Gravimetric analysis to obtain the formula of an unknown sulfate sample.