[kirk]

What is the difference between molarity and normality?

[Mr Peanut]

A mole is the molecular weight expressed in grams.

An equivalent is the "equivalent" weight expressed in grams.

An equivalent is the amount of a material that transfers one mole of a reactive species. For example an equivalent of an acid transfers one mole of protons. An equivalent of an oxidizing agent accepts one mole of electrons.

Finally, a 1 normal solution contains one equivalent of a given compound.

[Mr Peanut]

hat's:

Finally, a 1 normal solution contains one equivalent of a given compound in a liter.

[agrobert]

For example if your 1 M H₂SO₄ delivers two equivalent protons then it can also be called 2 N H₂SO₄.  For the same reason you can't have a 2 N HCl solution.

[Borek]

For the same reason you can't have a 2 N HCl solution.

What about 2M HCl?

kirk: take a look at

http://www.chembuddy.com/?left=concentration&right=molarity

http://www.chembuddy.com/?left=concentration&right=normality

[Mr Peanut]

For example if your 1 M H₂SO₄ delivers two equivalent protons then it can also be called 2 N H₂SO₄.  For the same reason you can't have a 2 N HCl solution.

Well, you can have 2 N HCl. It's just that it is the same as 2 M HCl.

[agrobert]

Yea you guys are right.  This confusion is why I think we should do away with Normality though.  As long as you understand molar equivalency and molarity then the Normality system is extraneous.