Solid Lead nitrate is dissolved in 1 litre of water. The solution was found to boil at 100.15$^\circ$C. When 0.2 mol of NaCl is added to the resulting solution, it was observed that the solution froze at $-0.8^\circ$ C. The solubility product of PbCl$_2$ formed is __________ $\times$ 10$^{-6}$ at 298 K. (Nearest integer)

Given : $\mathrm{K_b=0.5}$ K kg mol$^{-1}$ and $\mathrm{K_f=1.8}$ K kg mol$^{-1}$. Assume molality to the equal to molarity in all cases.