whupharm_xu
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temperature about 6N HCl under reflux
to make a solution of 6N HCl reflux,what temperatre should be controlled?is it 100?
it seems to be above 120.anybody can tell me the exact one?
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tom haggen
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Just out of curiosity what do the units "N" stand for in chemistry? I know they are newtons in physics but chemistry I'm not quite sure
because I haven't came across them yet.
N/A
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Mr. Wizard
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I believe it stands for Normal, which would be 1 Mole of a compound (6.023 x 10^23 molecules) in 1 liter of solution. This would allow you to
measure out Moles of a substance by the convenient method of measuring it's volume. In the previous post the person's solution contains 6
Moles per liter or 6 times (1(H)+35(Cl)) or 216 grams (approx ) in one liter of the
solution. Assuming no dumb errors, that's it in a nutshell.
I had to correct molecules for atoms whoops
[Edited on 26-4-2005 by Mr. Wizard]
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tom haggen
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What you’re describing I know as molarity which is giving as mols/liter. Usually It's describe with a "M" but I guess "N"
and "M" can be used interchangeably here.
N/A
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Mephisto
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whupharm_xu: Your 6 N HCl has a concentration of 22%. That's almost the concentration of the well known HCl-water-azeotrope, which boils at
108.58 °C and contains 20.22% HCl.
tom haggen: You've forgotten the equivalents. Normality isn't the same like Molarity, but you can say N = M * equivalents. 1 M HCl = 1 N
HCl, but 1 M H2SO4 = 2 N H2SO4...
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Mr. Wizard
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I was off a little on Normal vs Molality. Normal is the Molal equivalents for acids and bases. Here are the details:
http://www.carolina.com/chemistry/experiments/review.asp
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tom haggen
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To tell you the truth this subject makes me want to through up.
N/A
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Mr. Wizard
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| Quote: | Originally posted by tom haggen
To tell you the truth this subject makes me want to through up.
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MEDGO= My Eyes Doth Glaze Over
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whupharm_xu
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sorry,here i think, i must clarify that 6N HCl stands for 6 molar HCl in 1 liter water. hm... it's my neglect,and it is not a normal
expression.
thank you for all!
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azaleaemerson
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Wouldn't heating up such a concentrated acid solution simply distill off the HCl? The acid solution already fumes, right?
Curious.
azalea
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cyclonite4
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IIRC, HCl forms a 20% azeotrope (fixed boiling point mixture) with water, and I think 6M is less than 20% HCl (too lazy/tired to calculate now).
Hydrogen chloride won't just completely seperate from the water under heat.
\"It is dangerous to be right, when your government is wrong.\" - Voltaire
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whupharm_xu
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i got 6M HCl by mixing concentrated HCl(36%-38%,about 12mol/l) with equivalent volum distilled water,is it right?
here heating a solution of 6M HCl under reflux is just to make ester hydrolyze,not to remove HCl with heating.
these days i carry out an experiment in hydrolyzing certain ester. the literature shows this ester is hydrolized with 6M HCl under reflux for about
12h. but today i have not got an promising result. i always suspect the hydrolyzation is not completely finished.possibly the temperature is not
controlled right.
i haven't mastered english well,maybe somebody can't understand
clearly what i post.
sorry!
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Mephisto
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Your ester changes the boiling point of the mixture too. If you only have to reflux your mix, let it simply boil and it controls its boiling point
without your help.
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