What is the meaning of normality and its relation to molar concentration?

[WavesOfPhysics]

what does normality means, and how does it relate to molar concentration ?

 

[DrClaude]

http://en.wikipedia.org/wiki/Normality_(chemistry)

 

[epenguin]

Something that was much insisted on when I was at school, because i guess some kids found it hard to get their heads round. Like 1M HCl or NaOH are 1N but 1M H₂SO₄ or Na₂CO₃ are 2N. You get the idea? - it's the same as the distinction between molar masses and equivalent masses (or weights as we used to call them).

I think they have been phased out of teaching now, have they? If so it's no loss, they are unnecessary.

 

[Borek]

Normality meant different things at different moments in time. There was a period when normality depended on the reaction - so 1M sulfuric acid was 2N in the reaction with NaOH, but 1N inteh reaction with CaCl. Then IUPAC decided to make it always reaction with H⁺ or e^- - so 1M sulfuric acid would be always 2N. Then, IUPAC decided they created so much confusion it is better to deprecate normality at all.

 

[LudusRex]

Normality refers to the concentration of a solution in terms of its equivalent weight of solute per liter of solution. It is typically denoted by the symbol N and is expressed in units of equivalents per liter (eq/L). This is different from molar concentration, which is the concentration of a solution in terms of moles of solute per liter of solution.

In other words, normality takes into account the chemical valence of a solute, while molar concentration does not. For example, a solution of hydrochloric acid (HCl) with a molar concentration of 1 M has a normality of 2 N, because each molecule of HCl contains 1 mole of H+ ions and has a valence of 1, so 1 mole of HCl is equivalent to 2 moles of H+ ions.

Normality is often used in acid-base titrations, where the reaction between the acid and base is based on their equivalent weights rather than their molar weights. In this case, normality is a more accurate measure of the concentration of the solution.

In summary, normality is a measure of the concentration of a solution in terms of its equivalent weight of solute, while molar concentration is a measure of concentration in terms of moles of solute. Normality takes into account the valence of the solute and is often used in acid-base chemistry.