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)

$1.6\times {10}^5$

We know ,

$\pi V=nRT=\frac{w}{M}RT$

$\therefore 6\times {10}^{-4}\times 1=\frac{4}{M}\times 0.0821\times 300;\Rightarrow M=1.64\times {10}^5.$