We’re being asked to calculate the vapor pressure of water at 338K (64.85oC) above a solution of a nonvolatile solute in water having a boiling point of 380.4K. (107.25oC).
The vapor pressure of pure water at this temperature is 0.2467 atm.
Recall that the boiling point of a solution is higher than that of the pure solvent and the change in boiling point (ΔTb) is given by:
The change in boiling point is also related to the molality of the solution:
m = molality of the solution (in m or mol/kg)
Kb = boiling point elevation constant (0.512 ˚C/m)
A solution of a nonvolatile solute in water has a boiling point of 380.4 K .
Calculate the vapor pressure of water above this solution at 338 K. The vapor pressure of pure water at this temperature is 0.2467 atm.