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Topic: Question - boiling point of acid  (Read 2847 times)

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Offline DUser

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Question - boiling point of acid
« on: November 06, 2006, 09:29:20 AM »
Hello.I have one question.My eng is bad so try to understand me =)

If one 95% acid boils on 135 C ..what will be the boiling point of same acid but in 20% solution in wather ... (20% acid 80% wather)

Thanks ..

Offline DevaDevil

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Re: Question - boiling point of acid
« Reply #1 on: November 06, 2006, 06:43:52 PM »
To answer this you might want to check out the boiling point elevation in solvents

dT = Kb * m

dT = elevation of boiling temperature
Kb = constant of increase in boiling point per molal
m = molal of the solute (in your case the acid)

I'll give you the value of Kb in water: 0.52 oC m-1
First you calculate the molality of your 95% acid, then calculate back the molality of the 20% acid, and finally calculate the new boiling temperature.

PS. Remember, 1 molal = 1 mol soluted in 1000 g solvent

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