Ba(NO3)2 + Na2SO4 ==> BaSO4 + 2NaNO3
a. Gravimetric analysis depends upon almost none of the solid dissolving; adding and excess of Na2SO4 is adding a common ion (sulfate ion) which decreases the solubility of the BaSO4.
b. mols BaSO4 = grams/molar mass BaSO4 = ?
mols Ba(NO3)2 = mols BaSO4
grams Ba(NO3)2 = mols Ba(NO3)2 x molar mass Ba(NO3)2 = ?
%Ba(NO3)2 = (mass Ba(NO3)2/mass sample)*100 = ?
The concentration of barium ions in any solution can also be determined via gravimetric analysis. An impure sample of barium nitrate with a mass of 1.234 g, is completely dissolved in water and the resulting solution is reacted with an excess of aqueous sodium sulfate. A precipitate forms, and after filtering and drying, it was found to have a mass of 0.848 g.
A) What is the relevance of adding eccess sodium sulfate?
B) Calculate the % of barium nitrate in the original 1.234 g sample.
1 answer
1 answer