Question

Urea forms an ideal solution in water .Determine the vapour pressure of aqueous solution containing 10% by mass of urea of 4∘C.(Vapour pressure of water,at 40∘C=55.3 mm Hg)

Answer 1

Answer:

Vapour pressure of the solution is 53.516 mm of Hg

Explanation:

SUGGESTION :

I think both Temperatures must be given 40°C

.

FORMULAE :

1) Psol = P°water × Xwater

P°water = 55.3 mm Hg

Xwater = mole fraction of water in solution.

2) Xwater is to be found by formula given in attached photo.

Procedure :

That gives,

Xwater = 90÷18 = 30

90÷18 + 10÷60 31

Since,

GMWwater = 18g

GMWurea = 60g

mass of water taken. = 90% total mass

mass of urea taken. = 10% total mass

Answer :

Therefore, Psolution = 55.3× 30 = 53.516 mm Hg

31