Sea water contains 29 . 25 % NaCl and 19 % MgCl 2 by weight of solution. The normal boiling point of the sea water is C ∘ (Nearest integer) Assume 100 % ionization for both NaCl and MgCl 2 Given: K b H 2 O = 0 . 52 K kg mol - 1 Molar mass of NaCl and MgCl 2 is 58 . 5 and 95 g mol - 1 respectively.

Step-by-step solution

Molality of solution = moles   of   solute mass   of   solvent × 1000 Number of moles NaCl   = 29 . 25 58 . 5 = 0 . 5 Number of moles of MgCl 2 = 19 95 = 0 . 2 NaCl = 0 . 5 51 . 75 × 1000 MgCl 2 = 0 . 2 51 . 75 × 1000 ΔT b = i 1   m 1 + i 2   m 2 k b ∆ T b = Elevation in boiling point i = Van't Hoff factor m = molality k b = molal elevation constant ∆ T b = 2 × 0 . 5 × 1000 51 . 75 × 3 × 0 . 2 × 1000 51 . 75 × 0 . 5