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Topic: Rauolt's and Dalton's Law  (Read 5610 times)

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Offline trisha

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Rauolt's and Dalton's Law
« on: September 16, 2009, 12:03:55 PM »
(a) Using Dalton's and Raoult's Law derive an equation for the m.v.c. in the liquid state of an ideal binary liquid mixture in terms of pressure

(b) Calculate the mole fraction of the m.v.c. in a binary liquid mixture at a column     operating pressure of 110kNm-2 of Methanol [A] Water .
Data: Vapour Pressure of pure [A] and are 15 and 190kNm-2 respectively.


Offline typhoon2028

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Re: Rauolt's and Dalton's Law
« Reply #1 on: September 16, 2009, 01:34:45 PM »
This is a good problem for you to think about.

Do you know the formula for Rault's Law?  Do you understand how it is derived?

I could give you the solution, but you need to attempt the question first.

Offline trisha

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Re: Rauolt's and Dalton's Law
« Reply #2 on: September 17, 2009, 10:32:45 PM »
 No I was not in class that day anad its hard to get anybody's book borrowed to at least get notes. I searched the online but I still don't understand.

Offline typhoon2028

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Re: Rauolt's and Dalton's Law
« Reply #3 on: September 18, 2009, 08:18:01 AM »
http://en.wikipedia.org/wiki/Raoult%27s_law
http://en.wikipedia.org/wiki/Daltons_Law_Of_Partial_Pressure

What does m.v.c. stand for?  I am confused.

Pt = PaXa + PbXb

Pt = total pressure
Pa = vapor pressure of component A
Xa = mole fraction of component A in solution
Pb = vapor pressure of component B
Xb = mole fraction of component B in solution

The problem gives you Pt, Pa, & Pb.  The trick to the solution is knowing that is a binary mixture.
For a binary mixture:  Xa + Xb = 1
You can solve for Xb in terms of Xa:  Xb = (1 - Xa)

The deriving the equation in terms of pressure, becomes a basic algebra 2 problem.

I hope this helps

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