normality

[hoyas19]

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Ok so somehow in the 3 years of chemistry I've taken, I've never heard of normality. I read about it in Kaplan and come across problems using it in the destroyer but I still really just don't understand what it is and when it would be used. Can anyone explain it and when to use N1V1=N2N2 instead of M1V1 = M2V2? thank youu

 

[orthodocs12]

ok. so say u have 1M of NaOH, the normality would be 1. Why? Because there is only one H in the NaOH molecule. Lets say u have 1M of H2SO4, then the Normality would be 2, because u have 2 H's on the molecule. from there, u just solve: N1V1=N2V2. simple as that. Hope that helps!😀

 

[Sea of ASH]

in a nutshell, normality is the amount of H+ or -OH's you have.

HCl has one normal, NaOH also has one normal. but Ca(OH)2 has two normal.

 

[dr bojangles]

yes agree with above. normality refers to the molar equivalents that can participate in rxns. so, the titration curve of HCl has 1 equivalence point (linear portion of sigmoidal curve). but, the titration curve of H2SO4 has 2 linear portions, as each molar equivalent of H dissociates. to calculate, just multiply/divide. a 6M solution of H2SO4 is 12N.
good luck.

 

[msavaya]

Also remember that Normality is ALWAYS greater than or equal to Molarity...never less than.
If given two volumes but only 1 molarity of acids/bases, you can find the molarity of the other by the equation NaVa = NbVb

 

[doc toothache]

Normality (N) is defined as the number of equivalents per liter of solution:
N=M x 👎
For an acid solution, n is the number of H+ provided by a formula unit of acid. For a basic solution, n is the number of OH- provided by a formula unit of base.
In oxidation reduction the normality is equal to the molarity divided by the change in the oxidation state.

 

[Contach]

Normality (N) is defined as the number of equivalents per liter of solution:
N=M x 👎
For an acid solution, n is the number of H+ provided by a formula unit of acid. For a basic solution, n is the number of OH- provided by a formula unit of base.
In oxidation reduction the normality is equal to the molarity divided by the change in the oxidation state.

for redox.. wouldn't this make normality SMALLER than molarity? this is sin #1 isnt it?

what do u mean by "change in oxidation state"

thx

 

[doc toothache]

for redox.. wouldn't this make normality SMALLER than molarity? this is sin #1 isnt it?
what do u mean by "change in oxidation state"
thx

Admittedly it is a bit confusion. The first states that say in the case of H2SO4 the normality will be equal to the molarity x2. The second as a mathematical relationship. A change in oxidation/reduction from +5 to +2 with a total gain of 3 electrons would mean 3N= 1M for the compound in question.