Liquid Solution

What mass of solute (molar mass $58 \mathrm{~g} \mathrm{~mol}^{-1}$) is to be dissolved in $2.5 \mathrm{~dm}^3 \mathrm{~H}_2 \mathrm{O}$ to generate osmotic pressure of 0.245 atm at 300 K ?

\(\left(\mathrm{R}=0.0821 \mathrm{~dm}^3 \text { atm } \mathrm{K}^{-1} \mathrm{~mol}^{-1}\right)\)