At \( 27^\circ\text{C} \), a solution containing \( 2.5\,\text{g} \) of solute in \( 250.0\,mL \) of solution exerts an osmotic pressure of \( 400\,\text{Pa} \). The molar mass of solute is \( \_\_\_\_\,\text{g mol}^{-1} \). (Nearest integer)
(Given: \( R = 0.083\,\text{L bar K}^{-1}\text{ mol}^{-1} \))