Chapter 17 Principles of Chemical Reactivity: Other Aspects of Aqueous Equilibria - Study Questions - Page 677e: 97

a) PbSO4 b) $[Pb^{2+}]=5.13\times10^{-5}\ M$

a) Ksp of CaSO4: $4.93\times10^{-5}$ Ksp of PbSO4: $2.53\times10^{-8}$ PbSO4 will precipitate first because it has a lower Ksp b) $4.93\times10^{-5}=0.10\times[SO_4^{2-}]$ $[SO_4^{2-}]=4.93\times10^{-4}$ $2.53\times10^{-8}=[Pb^{2+}]4.93\times10^{-4}$ $[Pb^{2+}]=5.13\times10^{-5}\ M$