A solution containing $2.5 \times 10^{-3} \mathrm{~kg}$ of a solute dissolved in $75 \times 10^{-3} \mathrm{~kg}$ of water boils at 373.535 K . The molar mass of the solute is $\_\_\_\_$ $\mathrm{g} \mathrm{mol}^{-1}$. [nearest integer] (Given: $\mathrm{K}_{\mathrm{b}}\left(\mathrm{H}_2 \mathrm{O}\right)=0.52 \mathrm{~K} \mathrm{Kg} \mathrm{mol}^{-1}$, boiling point of water $=373.15 \mathrm{~K}$ )