Question

A solution containing 4 g of a non-volatile organic solute per 100 mL was found to have an osmotic pressure equal to 500 cm of mercury at ${27}^{o}C$.The molecular weight of solute is:

• A. 14.97
• B. 149.7
• C. 1697
• D. 1.497

Answer 1

Answer: (B)

149.7

$\pi V_2=\frac{W_2}{M{w}_2}RT$

$\frac{500}{76}\times \frac{100}{1000}=\frac{4}{M{w}_2}\times 0.0821\times 300$

$\therefore M{w}_2=149.7$

Hence, the correct option is $B$