Question

The solution containing $4.0gm$ of a polyvinyl chloride polymer in $1$ litre of dioxane was found to have an osmotic pressure $6.0\times 10^{-4}$ atmosphere at $300K$, the value of $R$ used is $0.082$ litre atmosphere $mol{e}^{-1}{K}^{-1}$ The molecular mass of the polymer was found to be

• A. $3.0\times 10^2$
• B. $1.6\times 10^5$
• C. $5.6\times 10^4$
• D. $6.4\times 10^2$

Answer 1

Answer: (B)

$\pi V=\frac{w}{m}RT$
$\therefore 6\times 10^{-4}\times 1=\frac{4}{m}\times 0.0821\times 300$
$\Rightarrow m=1.64\times 10^5$