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Author: Subject: calculating moler ratio of acids solutions?
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[*] posted on 10-8-2006 at 04:32
calculating moler ratio of acids solutions?


Is there a universal formula for figuring out how many moles of an acid are in a given solution?

I know that the hydrogen chloride molecule is 36.47g per mole but how many grams of 31.45% hcl solution does it take to equal 1 mole?
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jack-sparrow
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[*] posted on 10-8-2006 at 05:08


you have to divide your needed mass of acid by its concentration:

36.47 g / 0.3145 = 116 g of solution

another example :

you need 0.5 mol of HBr but you only have 48% HBr solution

0.5 mol * 81 g/mol = 40.5 g
40.5 g / 0.48 = 84.4 g
density = 1.49 g/ mL
84.4 / 1.49 = 56.6 mL so you measure 56.6 mL or 84.4 g it is up to you.




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[*] posted on 10-8-2006 at 07:27
brain freeze


Im not sure what the needed mass of acid is untill i figure out how much ml. or g. 1 mole of 31.45% hcl acid is.

From there I can easily figure out the amount of 31.45% needed for a certain reaction.
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[*] posted on 10-8-2006 at 07:36
hmm


you need 1 mole of hcl but only have 31.45% solution

1 mol x 36.47 = 36.47

36.47/3.145 = 11.6g

So 11.6g of this 31.45% hcl solution is 1 mole correct?

[Edited on 10-8-2006 by Punk]
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[*] posted on 10-8-2006 at 08:09


I mole of HCl IS 36.5 g/mol so you divide 36.5 / 0.3145 to get :

116 g of HCl solution at 31.45 %

I already gave you the answer.




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[*] posted on 10-8-2006 at 08:55


I just needed to move my decimal.

Thanks
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