Question

A solution containing 8 g of a carbohydrate in 100 g of water has a density 1.025 g / ml and the osmotic pressure of the solution at ${27}^{\circ }C$ is 5atm. The molar mass of the carbohydrate is

• A. 387
• B. 374
• C. 3740
• D. 480

Answer 1

The correct option is B 374

Wt of solution = 100 + 8 = 108g; Volume of solution $=\frac{108}{1.025}\times {10}^{-3}Litre$
$\pi =\frac{n}{V}RT=\frac{W\times R\times T}{M\times V};M=\frac{W\times R\times T}{\pi \times V}=\frac{8\times 0.0821\times 300\times 1.025}{5\times 108\times {10}^{-3}}=374$