Normality

[anteater85]

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I'm very confused about normality and its definition.
KBB has a question like this:
what is the normality of a 2M solution of H3PO4 for an acid-base titration?

I get that H3PO4 has 3 moles of H. Is true that if we doing the normality questions and we are working with acid-base titration we only look at the H and nothing else?

 

[Sublimation]

it would be the concentration times the Number of H that dissociate which with h3po4 is like 3 so normality i would assume is 6?...destroyer does a good job of explainign normality.

 

[nze82]

Normality is essentially the concentration of the reactive species. Consider the following formula:

N>=M (Normality is always equal or larger than molarity)

**Normality = Molarity in case of monoprotic acids (or bases). These are defined as acid and/or bases that only release one H+ or OH- (Example: HCl, NaOH). So, a 2M HCl has a noarmality of 2N.

**Normality > Molarity in case polyprotic acids (or bases). These are defined as acids and/or bases that release more than one H+ or OH- (Example: H2SO4). So, a 2M H2SO4 has a normality of 4N (2x2 = 4).

 

[anteater85]

Thank you so much

Normality is essentially the concentration of the reactive species. Consider the following formula:

N>=M (Normality is always equal or larger than molarity)

**Normality = Molarity in case of monoprotic acids (or bases). These are defined as acid and/or bases that only release one H+ or OH- (Example: HCl, NaOH). So, a 2M HCl has a noarmality of 2N.

**Normality > Molarity in case polyprotic acids (or bases). These are defined as acids and/or bases that release more than one H+ or OH- (Example: H2SO4). So, a 2M H2SO4 has a normality of 4N (2x2 = 4).