[ આપેલ : પાણીનો મોલલ ઉત્કલનબિંદુ ઉન્નયન અચળાંક $\left(\mathrm{K}_{\mathrm{b}}\right)=0.52 \mathrm{~K} . \mathrm{kg} \mathrm{mol}^{-1}$,
$1 \mathrm{~atm}$ દબાણ $=760 \mathrm{~mm} \mathrm{Hg}$, પાણીનું મોલર દળ $\left.=18 \mathrm{~g} \mathrm{~mol}^{-1}\right]$
\(\mathrm{m}=\frac{2}{0.52}\)
According to question, solution is much diluted
\(\text { so } \frac{\Delta \mathrm{P}}{\mathrm{P}^{\circ}}=\frac{\mathrm{n}_{\text {solate }}}{\mathrm{n}_{\text {soltron: }}}\)
\(\frac{\Delta \mathrm{P}}{\mathrm{P}^{\circ}}=\frac{\mathrm{m}}{1000} \times \mathrm{M}_{\text {solvent }}\)
\(\Delta \mathrm{P}=\mathrm{P}^{\circ} \times \frac{\mathrm{m}}{1000} \times \mathrm{M}_{\text {sohtwat }}\)
\(=760 \times \frac{\frac{2}{0.52}}{1000} \times 18=52.615\)
\(P_5=760-52.615=707.385 \mathrm{~mm} \text { of } \mathrm{Hg}\)