Question

A sample of air contains only o2, n2 and h2o. Its saturated with water vapours and total pressure is 640 torr. The vapour pressure of water is 40 torr and the molar ratio of n2:o2 is 3:1. The partial pressure of n2 is?

Answer 1

Let the ratio of moles of N2 : O2 :H2O be 3:1:x

Partial Presure of any gas = Mole fraction * Total Pressure

Partial Pressure of H2O vapour = 40 torr

40 = Mole fraction of H2O * 640

Mole fraction of H2O = 40/640

x/(4+x) = 40/640

x = 4/15

N2 : O2 :H2O = 3 : 1 : 4/15
= 45 : 15 : 4

Partial Pressure of N2 = Mole fraction of N2 * 640

= 45/(45+15+4) * 640 = 450 torr

Answer 2

Answer:

I am showing u the easiest solution to this question

Explanation:

the answer is 450 torr