150 mL of 0.0008M ammonium sulphate is mixed with 50mL of 0.04M calcium nitrate. The ionic product of CaSO₄ will be : (K_sp = 2.4 × 10^–5 for CaSO₄)

After mixing total volume =150 + 50 =200 ml

The ionic product after mixing $=\left[{\mathrm{Ca}}^{+2}\right]\times \left[{\mathrm{SO}}_4^{-2}\right]$

                        $=\left(\frac{50\times 0.04}{200}\right)\times \left(\frac{150\times 8\times {10}^{-4}}{200}\right)$

                         $={10}^{-2}\times 6\times {10}^{-4}$

                          $=6\times {10}^{-6}<{\mathrm{K}}_{\mathrm{sp}}$