GCHEM : Normality??

[Mrbubbles]

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ok, so i am reading about it in the Schaum's Outline Biology, and it compares Molarity from Normality or some sort.

ex) 2 NaOH + H2SO4 --> Na2SO4 + H20

"if we were to use 1L of 1M NaOH we would need 1 L of .5 M H2SO4 to provide sufficient acid for the rxn to occur. However, if we were measuring concentration using normality, for one L of 1 N NaOH, we would also use one liter of 1 N H2SO4. THis is because a 1 N solution of H2SO4 is also 0.5 M solution. SImilary a 1.0 N solution of H3PO4 is also .33M."

HELP?!! i still don't understand normality at all. HELP PLEASE! if u happen to read at least say, i don't get it.

can someone explain in plain english?

 

[rose786]

You'd probably have to bust out a textbook to fully understand Normality, or wiki it. In a nutshell, multiply the OH or H+ in a compound by the molarity. So for that rxn, Normality of NaOH is 2 x 1 = 2. For H2SO4, its 2 x 1 = 2.

Also keep in mind the equation N1xV1 = N2xV2. This is a variation of the M1V1=M2V2 equation you see in texts. I think I saw this in the destroyer, but I can't say for sure.

 

[Mrbubbles]

You'd probably have to bust out a textbook to fully understand Normality, or wiki it. In a nutshell, multiply the OH or H+ in a compound by the molarity. So for that rxn, Normality of NaOH is 2 x 1 = 2. For H2SO4, its 2 x 1 = 2.

Also keep in mind the equation N1xV1 = N2xV2. This is a variation of the M1V1=M2V2 equation you see in texts. I think I saw this in the destroyer, but I can't say for sure.

it's getting familiar to me....hmm..thank you , can anyone possible provide examples? i learn better that way.. i don't have my kaplan book on me, otherwise i'd read more on it ..i'm at work 😕

 

[LeeLoo84]

Hi, normality is very similar to molarity, except that it describes the number of EQUIVALENTS of something, usually protons/hydroxide ions. The important concept being that it considers all the individual dissociated parts of a compound in solution.

So for example:

HCl Hydrochloric acid only yields one H+ in solution, therefore it is 1N

H2SO4 Sulfuric acid yields 2 H+'s in solution, so it would be 2N, twice the normality of the first acid.

KOH Potassium Hydroxide yields one OH- upon dissociation = 1N
Ba(OH)2 Barium hydroxide yields 2 OH-'s so again, it is at twice the normality

Molarity describes the concentration of the actual compound itself, not the components, in solution.

Hope this helps!

 

[bigstix808]

i like the way kaplan put it, "Norm is the Mol of the stuff in question taking place in the rxn". that's how i've always kept it straight.

 

[klutzy1987]

normality is the moles of H+ ions or the number oh OH- ions discosciating multiplyed by the molarity. You use normality for titrations mixing etc...

It is explained very well in the destroyer.