I have a solution containing $0.2\:\mathrm{mol}$ of $\ce{Br^-}$ ions and $\ce{SO_4^2-}$ ions each.
Now if I add excess $\ce{AgNO3}$ in this solution,
what will precipitate?
$\ce{Ag2SO4}$ or $\ce{AgBr}$ or both?

And if I add just $0.2\:\mathrm{mol}$ of $\ce{AgNO3}$, what will precipitate?

(I don't want to calculate anything. Just wanted to know qualitatively that which compound precipitates.)


1 Answer 1


You need to know that $K_\mathrm{sp}$ is used to determine the solubilities of sparingly soluble salts usually. You can get the values of $\ce{AgSO4,AgBr}$ and as $K_\mathrm{sp}=[\ce{Ag+}]^2[\ce{SO4^2-}]$ or $[\ce{Ag+}][\ce{Br-}]$. Now concentration of silver ion is constant so try calculating the other two anions and try comparing them.

  • $\begingroup$ So in excess both will precipitate eventually while in limited quantity, the one with lower Ksp will precipitate? $\endgroup$
    – pikachu
    Commented Apr 19, 2015 at 6:31
  • 1
    $\begingroup$ @pikachu i think you got it right. $\endgroup$
    – RE60K
    Commented Apr 19, 2015 at 9:50

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

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