Question

Titration of a weak acid with a strong base. the ph curve for titration of 50.0ml of a 0.100 M of acetic acid with a 0.100 M solution of NaOH (aq). For clarity, water molecules have been omitted from the molecular art.

a) If the acetic acid being titrated here were replaced by hydrochloric acid, would the amount of base needed to reach the equivalence point change?

b) Would the pH at the equivalence point change?
-yes the pH at the equivalence point will increase.
-yes the pH at the equivalence point will decrease.
-no the pH will not change

Answer 1

a) Amount of base needed to reach the equivalence point does not change by change the acid. Because number of H+ ions in 50.0mL of 0.1M acetic acid is equal to number of H+ ions in 50.0mL of 0.100M HCl.

b) Titration of acetic acid with strong base produce conjugate base of acetic acid (acetate) at equivalence point. It is weak base and solution will have pH greater than 7.

Titration of HCl with strong base will produce neutral salt at equivalence point. So it will have pH= 7.

So answer is

yes the pH at the equivalence point will decrease.