How do I find out the concentration?

Question

I've got a diagram of two titrations; one of a weak (HAc) and one of a strong (HCl) acid, both with NaOH dripping down on 'em.

The Y-shoulder shows the pH value while the X-shoulder shows the number of ml added NaOH.

How do I find out the concentration of HCl and HAc from this?

Thank you for a prompt answer.

How would I do a normal titration calculation? :) That was kind of the main trouble!

Answer 1

You draw a vertical line down from half way up the steepest portion of the rising curve, so that it hits the x-axis. Then read off the volume of added NaOH.

Then a normal titration calculation will do the trick!

Answer 2

HAc + NaOH --> NaAc + H2O
HCl + NaOH --> NaCl + H20

Since both reactions are 1:1 (one mole reactant yields one mole product) you can use the concentration of the NaOH (should be given in Molarity) times the volume of NaOH (from the curve in Liters) to determine the moles of NaOH needed to neutralize the 2 acids. Do this for each titration curve.

This mole number can then be divided by the volume of the acid (in Liters) before the titration began to give you the concentration.