Hi, I need help figuring out this question.

An impure sample of barium hydroxide, Ba(OH)2 (aq), has a mass of 0.540 g. It is dissolved in water and then treated with excess sulfuric acid, H2SO4(aq). This results in the formation of a precipitate of barium sulfate, BaSO4(s).

Given balanced chemical equation:
H2SO4(aq) + Ba(OH)2(aq) --> BaSO4(s) + H2O(l)

The barium sulfate is filtered, and any remaining sulfuric acid is washed away. Then the barium sulfate is dried and its mass is measured to be
0.62 g. What mass of barium hydroxide was in the original (impure) sample?

//I know 0.62 g is supposed to be the actual yield. I'm guessing that I am supposed to find the theoretical yield of barium sulfate and use that to find barium hydroxide but I can't figure out how to get there.

1 answer

find the moles of barium in the sulfate
... these are the moles that were in the original (impure) sample

use the moles to find the moles (and mass) of the barium hydroxide