Answer to Question #111242 in General Chemistry for Jonathan

Question

At a temperature of 27°C, the vapor pressure of water is 26.7 torr. If 80g of HNO3 are added to 750g of H2O, what will the vapor pressure of the solution be?

Answer 1

The relative decrease in the partial pressure of the solvent vapor over the solution does not depend on the nature of the solute and is equal to its molar fraction in the solution.

If vapor pressure of water is 26.7 torr (Pressure Pure solvent molar fraction=1).

Molar fraction with HNO3 solution : 750/(750+80)=0.9036

Vapor pressure of solution: 26,7*0.9036=24,12 torr