A solution containing 2 . 5 × 10 - 3 kg of a solute dissolved in 75 × 10 - 3 kg of water boils at 373 . 535 K . The molar mass of the solute is mol - 1 · [nearest integer] (Given : K b H 2 O = 0 . 52 K kg mol - 1 and boiling point of water = 373 . 15 K )

Step-by-step solution

ΔT b = iK b m ΔT b = Elevation   of   boiling   point K b =   molal   boiling   point   elevation   constant m = molality i = van ' t   hoff   factor m = 2 . 5 M × 1000 75 ∆ T b = T b - T b o T b = Boiling   point   of   the   solution T b o = Boiling   point   of   the   solvent ∆ T b = 373 . 535 - 373 . 15                 = 0 . 385   K ΔT b = iK b m