Answer:
Boiling point of pure liquid is 135.4°C
Explanation:
The boiling point elevation (Colligative property of solutions) follows the formula:
ΔT = Kb×m×i
<em>ΔT is equal to increase in boiling point (Boililng point solution - boiling point pure liquid), Kb is boiling point elevation constant of the liquid, m is molality of solution and i is Van't Hoff factor.</em>
<em>Molality of solution (Moles urea / Kg X):</em>
Moles urea: 31.98g * (1mol / 60.06g) = 0.53247 moles
-60.06g/mol = Molar mass urea-
In 650g = 0.650kg:
0.53247 moles urea / 0.650kg = 0.8192m
Van't Hoff factor of urea is 1
Replacing in the equation:
ΔT = Kb×m×i
ΔT = 1.97°CKgMol⁻¹×0.8192m×1
ΔT = 1.6
As the solution boils at 137°C:
ΔT = Boililng point solution - boiling point pure liquid
ΔT = 1.6°C = 137.0°C - boiling point pure liquid
Boiling point of pure liquid is 135.4°C
