Question

How many mL of the NaOH solution needs to be added to reach the equivalence point of the hydrochloric acid-sodium hydroxide titration?

Only given information is 50cm3 base was added at 0.1 M to 25cm3 of HCl at 0.1M. I have created a graph in excell but I'm unsure if I need it to work this out? Help on the method would be great thank you.

Answer 1

The reaction between HCl and NaOH is

HCl (aq) + NaOH (aq) = NaCl (aq) + H₂O (l)

Hence 1 mole of HCl eacts with 1 mole of NaOH to produce 1 mole of NaCl and 1 mole of water.

So at the equivalent point, all HCl will react with NaOH with the same molarity.

We can write V₁ S₁ = V₂ S₂ or, 25 mL x 0.1 M = V₂ x 0.1 M   or, V2 = 25ml x (0.1 M / 0.1 M) = 25 mL

Thus 25 mL of the NaOH solution needs to be added to reach the equivalent point of the titration.