Normality to moles?

[pfaction]

I highly doubt N will be on there, but I tried to logic this passage out. It said "25mL of 0.2N H2SO4". So I took that to be 0.1 MOLAR of H2SO4.

I know this is correct since 0.3M H3PO4 is 0.9N. So the way I made a formula is N=[#H needed to neutralize][Molarity acid]

I then did 0.1M/1000 = x/25; where it came out to be 0.0025 moles.

A student neutralized it with 20mL of NaOH. How much NaOH?
So I set it up...2.5x10^-3 / 2x10^-2, got 0.125, and was wrong.

How did I do this wrong?

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[MrNeuro]

You're neutralizing it all the way have to use N * L get moles and that's how many miles of OH- you needs. I'm like 75% sure about this. It was a question in TBR G CHEM that was destroying me.

 

[kasho11]

Right, you need to use normality here because it accounts for the diprotic nature of H2SO4. But it is a somewhat low yield topic, possibly only a discrete or two on it might show up. I really hate complicated tension problems and I'm praying nothing hard shows up for me.

 

[pfaction]

You're neutralizing it all the way have to use N * L get moles and that's how many miles of OH- you needs. I'm like 75% sure about this. It was a question in TBR G CHEM that was destroying me.

That's exactly what I had problems with. That's why I made this topic. So I now know we need to use L*N, but why are we using L*N. N = [#H][Molarity] and molarity = moles/L. I don't see how I am wrong.