Question

If 0.340 mol of a nonvolatile nonelectrolyte are dissolved in 3.10 mol of water, what is the vapor pressure PH2O of the resulting solution? The vapor pressure of pure water is 23.8 torr at 25 ∘C . Express your answer with the appropriate units.

Answer 1

Answer:

21.4 torr

Explanation:

The vapour pressure of a solution is lower than that of the pure solvent. And according to Raoult's law this depends of the amount of solute in the solvent. It is calculated according to the following equation

$P_{A} =X_{A} P^{o} _{A}$

where $P_{A} is the pressure of the solution\\ X_{A} is the mole fraction of the solvent\\ P^{o}_{A}is the mole fraction of pure solvent$

$P_{A}=\frac{3.10 mol}{3.10mol+0.340mol}*23.8torr=21.4torr$