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Topic: normality  (Read 7227 times)

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tanya

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normality
« on: February 19, 2006, 04:28:23 PM »
what is the normality of a solution that has a concentration of 106.41 g/dL of H2SO4????how do I figure out a prob. like this??

Offline Albert

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Re:normality
« Reply #1 on: February 19, 2006, 04:32:04 PM »

tanya

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Re:normality
« Reply #2 on: February 19, 2006, 04:43:33 PM »
i don't understand...

Offline Albert

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Re:normality
« Reply #3 on: February 19, 2006, 06:33:25 PM »
106.41 g/dL

Are you sure about it? It sounds too high.

Offline AWK

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Re:normality
« Reply #4 on: February 20, 2006, 03:19:03 AM »
1 equivalent = molecular mass/2.
Normality like molarity shold be calculated for 1 liiter of solution.
To Albert - concentrated H2SO4  is about 18M or 36N
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Offline Borek

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Re:normality
« Reply #5 on: February 20, 2006, 03:46:24 AM »
1 equivalent = molecular mass/2.
Normality like molarity shold be calculated for 1 liiter of solution.
To Albert - concentrated H2SO4  is about 18M or 36N

Especially when H2SO4 is used for Ba2+ precipitation ;)
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Offline AWK

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Re:normality
« Reply #6 on: February 20, 2006, 06:41:41 AM »
http://www.furrowpump.com/Applications/JarTesting/Explanationph.htm

Genereal idea for using normality is to simplify stoichiometry of reaction to 1:1 ratio of reagents.
Hence normality may depends on reaction used. But if not stated, for which reaction the reagent should is involved, some general rules are used.
Denominator (n) in formula MM/n for calculation of equivalents is
For acids - number of exchangeable protons
for bases - number of exchaneeable hydroxyl groups
For salts - number of total charges of cations or anions

For an example of the specific reaction (stated by Borek)
Ba(2+) + SO4(2-) =BaSO4(s)
we can use general rules or its extension, just for this reaction (n=1 for both reagents), and still stoichiometry will be 1:1.
For the reaction, eg
NaCl + H2SO4 = NaHSO4 + HCl (this is stoichiometry for RT) we should use n=1 for H2SO4
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