Question

The osmotic pressure of solutions of PVC in cyclohexanone at $300K$ are plotted on the graph.
The molar mass of $PVC$ is ____$gmo{l}^{-1}$ (Nearest integer)

Answer 1

Answer: 41500

$\pi =M^{\prime }RT=\left(\frac{W/M}{V}\right)RT$
$\Rightarrow \pi =\left(\frac{W}{V}\right)\left(\frac{1}{M}\right)RT=C\left(\frac{RT}{M}\right)$
$\Rightarrow \frac{\pi }{C}=\frac{RT}{M}\ne f(c)$
If we assume graph between $\frac{\pi }{C}$ and $C$

Assuming $\pi$ vs $C$ graph
Slope $=\frac{RT}{M}=\frac{0.083\times 300}{M}=6\times 10^{-4}$
$\therefore M=\frac{0.083\times 300}{6\times 10^{-4}}=\frac{830\times 300}{6}$
$=41,500gm/mole$