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Topic: what are 'mole fractions'?  (Read 5982 times)

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Misha

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what are 'mole fractions'?
« on: May 16, 2005, 10:07:17 PM »
I have a problem that states the following:
Calculate the mole fractions in a solution that is made of 25.0 g of ethyl alcohol, C2H5OH and 40.0g of water.

My question is, what are 'mole fractions'?
« Last Edit: May 16, 2005, 10:49:07 PM by Mitch »
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Offline Mitch

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Re:Mole Fractions?
« Reply #1 on: May 16, 2005, 10:48:31 PM »
Well first convert everything from gams to moles and then we'll move on from there.
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Offline Borek

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Re:what are 'mole fractions'?
« Reply #2 on: May 18, 2005, 06:12:29 AM »
Less then 30 seconds using CASC  :)

Molar fraction: express amount of every substance in solution in moles. Sum the moles. Divide moles of substance by the total moles of all substances - that's the molar fraction.
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Nano

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Re:what are 'mole fractions'?
« Reply #3 on: May 18, 2005, 07:06:14 PM »
mole fraction is like partial pressure in gas?
a quick thought :-X
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Offline Borek

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Re:what are 'mole fractions'?
« Reply #4 on: May 18, 2005, 07:12:24 PM »
There is some analogy. The main difference is that sum of all molar fractions is always 1, while the sum of partial pressures is just total pressure.
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Nano

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Re:what are 'mole fractions'?
« Reply #5 on: May 19, 2005, 06:05:25 PM »
Quote from: Borek on May 18, 2005, 07:12:24 PM
There is some analogy. The main difference is that sum of all molar fractions is always 1, while the sum of partial pressures is just total pressure.
Learn a new lesson, thanks!
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