Name: Solutions Which Deviate From Ideal Behaviour
Uploaded: 2019-07-19
Duration: 6 min 38 s
Description: Non-ideal solutions are the solutions that do not follow Raoult's law at all in their compositions. Let's discuss how these solutions deviate from ideal beha...

Question

The vapour pressure of pure liquids A and B are

450

and

700 mm Hg

respectively, at

350 K

. Find out the composition of the liquid mixture if total vapour pressure is

600 mm Hg

. Also find the composition of the vapour phase.

Accepted Answer

Given :- $P_{A}^{0} = 450 mm, P_{B}^{0} = 700 mm, P_{T} = 600 mm$

According to Raoult's law,

$P_{total} = P_{A} + P_{B}$

$= X_{A} P_{A}^{0} + X_{B} P_{B}^{0}$

$= X_{A} P_{A}^{0} + (1 - X_{A}) P_{B}^{0}$

$= X_{A} P_{A}^{0} + P_{B}^{0} - P_{B}^{0} X_{A}$

$= P_{B}^{0} + X_{A} (P_{A}^{0} - P_{B}^{0})$

$600 = 700 + (450 - 700) X_{A}$

$X_{A} = 0.40$

$X_{B} = 1 - 0.40 = 0.60 P_{A} = X_{A} P_{A}^{0} = 0.40 \times 450 = 180 mm P_{B} = X_{B} P_{B}^{0} = 0.60 \times 700 = 420 mm$

Mole fraction of $A$ in vapour phase $= \frac{P_{A}}{P_{A} + P_{B}} = \frac{180}{180 + 420} = 0.30$

Mole fraction of $B$ is $= 1 - 0.30 = 0.70$

Andhra Pradesh Board Solutions for Chapter: Solutions, Exercise 3: Intext Questions

Andhra Pradesh Board Chemistry Solutions for Exercise - Andhra Pradesh Board Solutions for Chapter: Solutions, Exercise 3: Intext Questions

Questions from Andhra Pradesh Board Solutions for Chapter: Solutions, Exercise 3: Intext Questions with Hints & Solutions

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