Anyone remember this from chem??

[E'01]

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Guys what's the relationship and conversion factor between Normal and Molarity?

 

[Coalboy]

Normal is essentially "what is the molarity of something I'm interested in in the solution" and is used mainly for polyprotic acids or other things that dissociate in solution.

HCl has one proton
1 Normal = 1 M

H2SO4 has two protons
1 Normal = 0.5 M
That is, each molecule of sulfuric acid will dissociate to give you 2 protons, so 0.5 M sulfuric acid will give you 1 M of protons (it's a strong acid).

Hope this helps.

 

[E'01]

Thank you Coalboy! Now, when exactly would you use this...say in a lab..

 

[Mossjoh]

Let me get this one!!!

Well, lets say we have 1 mole of H2SO4. We need to neutralize this with a base. However, how much do we need? Lets say we want to use NaOH. NaOH is 1 Normal since when it dissociates one hydroxide is given off. Therefore, if we wanted to neutralize the 1 mole of H2SO4, we would need 2 moles of NaOH. This is because the H2SO4 is 2 normal, and would give 2 protons for every molecule dissociated. Therefore, we need 2 moles of 1 Molar NaOH.

Mossjoh

 

[E'01]

I love the enthusiasm 🙂 Thank you both! I just reember praying that that would not be on the MCAT...I don't know why it's not that hard a concept, but I nevr really understood it. 🙁