Answer: The vapor pressure of the solution at is 29.86 mm Hg
Explanation:
As the relative lowering of vapor pressure is directly proportional to the amount of dissolved solute.
The formula for relative lowering of vapor pressure will be,
where,
= relative lowering in vapor pressure
i = Van'T Hoff factor = 1 (for non electrolytes)
= mole fraction of solute
=
Given : 9 moles of are dissolved in 50 L or 50000 ml of water
mass of water =
moles of solvent (water) =
Total moles = moles of solute + moles of solvent = 9 mol + 2778 mol = 2787
= mole fraction of solute
=
Thus the vapor pressure of the solution at is 29.86 mm Hg