[tvtokyo]

Hi some question on ideal solution. Do help thanks!
Qn:
Lets say a solution contain ethanol and choloroform.
Mole fraction of chloroform in solution = 0.990
The vapour in equilibrium with the solution has a pressure of 438.6 torr.
Mole fraction of choloroform in the vapour = 0.979.

(i) Calculate the partial pressure of each component in the vapour phase

Is it
P (chloroform) = 0.979*438.6 = 429 Torr
P (ethanol) = 438.6-429 = 9.21

(ii) The vapour pressure of pure choloroform
According to Raoult's law
P* (chloroform) = 429/0.990 = 433 Torr

[Borek]

Looks OK to me.

[mjc123]

How does 438.6 - 429 = 9.21?
Oh, it's because 0.979*438.6 = 429.39
Leave the decimal places in and round off the answer at the end.