Question

30 gram of urea is dissolved in 846 gram of h2o calculate the vapour pressure of h2o for this solution if the pressure of pure water at 298 kelvin is 23.8 mm of hg

Answer 1

Vapour pressure of solution = mole fraction of solvent × vapour pressure of pure solvent.

Mole fraction = mole of solvent / total moles.

Moles of water = 860 / 18 = 47.78 moles

Moles of urea = 30 / 60= 0.5moles

Total moles = 0.5 + 47.78 = 48.28

Mole fraction water = 47.78/48.28 = 0.9896

Vapour pressure of solution = 0.9896 × 23.8 = 23.55

Answer :

23.55 mm of hg

Answer 2

Answer:

Explanation:

Vapour pressure of solution = mole fraction of solvent × vapour pressure of pure solvent.

Mole fraction = mole of solvent / total moles.

Moles of water = 860 / 18 = 47.78 moles

Moles of urea = 30 / 60= 0.5moles

Total moles = 0.5 + 47.78 = 48.28

Mole fraction water = 47.78/48.28 = 0.9896

Vapour pressure of solution = 0.9896 × 23.8 = 23.55

Answer :

23.55 mm of hg