Question

At $27^{\circ} C$, a solution containing $25 \,g$ of solute in $2500 \,mL$ of solution exerts an osmotic pressure of $400 \,Pa$. The molar mass of the solute is ____ $g\,mol ^{-1}$. (Nearest integer)
(Given : $R =0.083 \,L\,bar\, K ^{-1} \,mol ^{-1}$ )

Answer 1

$\pi=CRT$
$\frac{400Pa}{10^5}​=\frac{\frac{​2.5g}{M_o}​}{\frac{250}{1000L}}​\times0.83\frac{L−bar​}{K⋅mol}\times300K$
$M_o​=62250$

So, the answer is 62250.