4
$\begingroup$

Which is a better way to obtain barium sulfate precipitate for gravimetric analysis: by adding $\ce{Ba^2+}$ ions to sulfate ion solution, or the other way round? I think it is better to precipitate sulfate ions by $\ce{BaCl2}$ solution, as this causes chloride ions to coprecipitate.

$\endgroup$
1
$\begingroup$

I think $\ce{BaCl2}$ should be added later. This is because $\ce{BaCl2}$ is soluble in water, but the metal sulphate you will be given may not be soluble. So if you add $\ce{M2SO4}$ later, you may get a wrong result as you have to make sure that the whole of $\ce{BaCl2}$ is used up. On the other hand all chloride salts are soluble. So while filtering the $\ce{MCl}$ will be removed easily along with the solvent and you will get $\ce{BaSO4}$.

$\endgroup$
  • $\begingroup$ I don't think so. Not all chloride salts are soluble and some sulfates are soluble enough. I want to hear an opinion from the precipitation point of view. $\endgroup$ – Uros Nov 26 '15 at 19:27

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.