\( \Rightarrow \,\,2\,\, = \,\,\frac{{1000\,\, \times \,\,2.5\,\, \times \,\,0.76\,\, \times \,\,1}}{{m\,\, \times \,\,100}}\)
\(m\, = \,\,12.5\,\, \times \,\,0.76\)
\(\frac{{{P^0}\, - \,\,{P_s}}}{{{P^0}}}\,\, = \,\,\frac{n}{N}\)
\(\frac{{760\,\, - \,\,{P_s}}}{{760}}\,\, = \,\,\frac{{2.5}}{{12.5\,\,\, \times \,\,0.76}}\,\, \times \,\,\frac{{18}}{{100}}\,\,\,\)
\( \Rightarrow \,\,{P_s}\,\, = \,\,724\)
$(M.wt.$ of $CuCl_2 =134.4 $ અને $K_b = 0.52\, , molal^{-1})$
(અણુભાર : $CHCl_3 = 119.5\, u, CH_2CI_2 = 85\,u$)