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> Suppose we have a 10mL solution that contains 0.02M $\ce{Ag^+}$ and 0.04M $\ce{Ba^{2+}}$. a) Find the necessary volume to be added of $\ce{HCl}$ to separate all the silver. (**Assume to be separated if there is less than 0'1% of remaining silver in the solution of what it was initially**)
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So here I tried to do it using the constant of solubility that is given to be $Ks(AgCl)=1.8\*10^{-10}$ noting that that new concentration of silver has to be 0'1% of the initial one, which means to me $[Ag^+]'=\frac{0.1}{100}[Ag^+]\_0$ hence using the constant: $$Ks(AgCl)=[Ag^+]'[Cl^-]'=[Ag^+]'(s+c\_{\text{added}})$$ because we have added some quantity to the solubility of $\ce{Cl-}$, and then since the constant is of the order of $10^{-10}$ we can approximate to $s\approx 0$: $$Ks(AgCl)=0.001[Ag^+]\_0\cdot c\_{\text{added}}\implies c\_{\text{added}}=\frac{Ks(AgCl)}{0.001[Ag^+]\_0}$$ but I don't think that's right since I don't get the answer that my books suggests.