Question

The solution containing 10 grams of an organic compound per litre showed an osmotic pressure of 1.18 atm at 0${}^0$C. Calculate the molecular mass of the compound.

[$R=$ 0.0821 $litre-atm{K}^{-1}{mole}^{-1}$]

• A. $189.94$
• B. $78$
• C. $94.5$
• D. $120$

Answer 1

The correct option is A $189.94$

$T=0^{o}C=273K$

$\pi =CRT$

$1.18=\frac{10}{M.\omega t}\times 0.0821\times 273$

$M.\omega t=\frac{10\times 0.0821\times 273}{1.18}$

$M.\omega t=189.94$ g/mole

Hence, option A is correct.