Calculate the boiling point elevation of solution if 15 g urea is dissolved in 1000 g water. [ K _ b for water =0.52 ~K ~kg ~mol ⁻¹ ; molar mass of urea =60 ~g ~mol ⁻¹ ]

Step-by-step solution

Boiling point elevation depends on molality through the relation T_b = K_b m . For this solution, 15 g of urea (molar mass 60 g mol ⁻¹ ) corresponds to n₂ = 15 60 = 0.25 mol . With 1000 g ( 1 kg ) of solvent, the molality is m = 0.25 1 = 0.25 mol kg ⁻¹ . Using the ebullioscopic constant for water K_b = 0.52 K kg mol ⁻¹ , the elevation becomes T_b = 0.52 0.25 = 0.13 K . The boiling point elevation is 0.13 K .