Question

The vapour pressure of water at 20°C is 17 mm Hg. Calculate the vapour pressure of solution containing 2.8 g of urea (NH₂CONH₂) in 50 g of water N = 14, C = 12, O = 16, H = 1, (16.71 mm Hg)

Answer 1

Answer:

given,

p1^o= 17mmHg

W1=50g

W2=2.8g

M1=18g

M2=NH2CONH2

=14+2(1)+12+16+14+2(1)

=60g

p=?

we know that,

p1^o - p W2 x M1

----------- = --------------

p1^o M2 x W1

= 17-p / 17 = 2.8 x 18/ 60 x 50

= 51000- 3000p = 856.8

= 51000- 856.8 = 3000p

= p = 16.71