Weak acids?

This is really more of a conceptual question than anything.
(I realize how sad/odd it is that I'm asking conceptual questions about chemistry on a Maplestory fansite. Oh well.)

Now, here's a problem from my homework.



I get how to do it and all, find the # of moles of OH- in the sodium hydroxide, set that equal to the # of moles of H+, and find how much volume of acid that equates to. Yada yada.

My question is this. According to the answer I get, it takes twice as much NaOH to neutralize the HC[SIZE="1"]2[/SIZE]H[SIZE="1"]3[/SIZE]O[SIZE="1"]2[/SIZE] than the HCl. Suppose the molar concentrations were the same, then it would take the same amount of NaOH for both.

However, acetic acid is a weak acid, so (I thought) it should require less base to neutralize it than for a strong acid like HCl. But that's not what the problem answer says.

So am I wrong, and weak acids and strong acids are actually equally capable of neutralizing a strong base (per mole), or is it something else I don't understand?

Everything deals with the pH curve. The pH does not significantly change until it is about to change from acidic to basic (weak acid). Thats why there is a sort of psuedo flat line, in which pH = pKA + log (A-/HA). Also you have to look at the mesure of Ka values of the acid versus the Kb of the base.

However in a strong acid, that point never happens because the acid and base quickly form a neutral salt.