Three 15.0-mL acid samples—0.10 M HA, 0.10 M HB, and 0.10 M H2C¬are all titrated with 0.100 M NaOH. If HA is a weak acid, HB is a strong acid, and H2C is a diprotic acid, which statement is true of all three titrations?

All three titrations require the same volume of NaOH to reach the first equivalence point.

Explanation:

Statements are:

All three titrations have the same final pH.

All three titrations require the same volume of NaOH to reach the first equivalence point.

All three titrations have the same pH at the first equivalence point.

All three titrations have the same initial pH.

The pH of the titration depends of the nature of the acid: If the acid is a strong acid, pH at the equivalence of the titration is 7. For a weak acid equivalence point depends of the nature of the conjugate base and initial pH of the weak acid. For a diprotic acid also depends of the nature of the acid.

Thus:

All three titrations have the same initial pH, All three titrations have the same pH at the first equivalence point. and All three titrations have the same final pH.  are the three FALSE.

As the concentrations of the acids is 0.10M and are titrated with 0.100M NaOH, The volume to reach the first equivalence point is the same for all the three acids.

Thus: