Question

5 g of a polymer of molar mass $50kgmo{l}^{-1}$ is dissolved in $1d{m}^3$ solution. The height of solution (mm) that will represent its osmotic pressure if density of solution at equilibrium is 0.96 $kgd{m}^{-3}$ is (divide answer by 5 and write nearest integer value).

Answer 1

Given, $n=\frac{5\times {10}^{-3}}{50};V=1d{m}^3=1\times {10}^{-3};T=300K$
$\therefore \Pi =\frac{nST}{V}=\frac{5\times {10}^{-3}\times 8.314\times 300}{50\times 1\times {10}^{-3}}=249.42N{m}^{-2}$
Since, $\Pi =hdgd=0.96kg/d{m}^3=0.96\times {10}^{3}kg/m^3$
$\therefore h=\frac{249.42}{0.96\times {10}^3\times 9.81}=0.0265m$
$=26.5mm$