Is this right??????????

[zibb3r]

Hi Guys,

Q: Use the molar masses of barium and sulfate to calculate the mass of sulfate ions in the Barium Sulfate solution?

A (by vea {thanks vea!}): BaSO4---->Ba2+ + SO4 2-

So the mole ratio for BaSO4 and SO4 2- is 1:1.

n(SO4 2-)=n(BaSO4)=0.0327mol

m(SO4 2-)= no. of mole X molar mass
=0.0327 X (32.07+64.00)
=3.141g (4 significant figures)

Would the question be asking the same thing if the question was: Use the molar masses of barium and sulfate to calculate the mass of sulfate ions in the precipitate formed?  Or Not??

Thanks Everybody for your help!!!!   

[huaxiadragon]

If all your calculations are correct, then I would say you are quite right.

Yes, they would be asking the same thing if they are asking the mass of sulfate ions in the precipitate.

Often this type of question is followed up with something like

To what assumption did you make?
and you have to say, I assumed ALL of the sulfate ions precipitated in order for the mass calculated to be correct.