The Grass Doctor

vapor pressure?

Urea, (NH2)2CO, which is widely used in fertilizers and plastics, is quite soluble in water. If you dissolve 9.00g of urea in 10.00mL of water, what is the vapor pressure of the solution at 24C? Assume the density of water is 1 g/mL. The vapor oressure of pure water at 24C IS 22.4 Torr.

Public Comments

1. Vapor pressure is quite simple. You need to multiply the original vapor pressure by the mole fraction of water. Mole fraction is mol of component(water in this case)/ mol total in solution Mol of urea= .15 mol by converting those grams To get mol of water, multiply the mL H20 by the density to get the grams. 10mL *(1g/mL)= 10 g water= .55 mol in total you have .7 mol, the mol fraction of water is .55/.7=.79 (.79)*(22.4)=17.7 torr...notice it is quite close