Answer to Question #183654 in General Chemistry for sards

Question

Given:

Titrant NaOH

Analyte HCl

pH at HALF-WAY point 5.47

Volume at HALF-WAY point 4.50

pH at EQUIVALENCE POINT 7.00

Volume at EQUIVALENCE POINT 10.71

Given:

Titrant NaOH

Analyte HC2H3O2

pH at HALF-WAY point 8.35

volume at HALF-WAY point 4.13

pH at EQUIVALENCE POINT 10.64

Volume at EQUIVALENCE POINT 4.70

Given:

Titrant HCl

Analyte NH3

pH at HALF-WAY point 3.55

volume at HALF-WAY point 8.00

pH at EQUIVALENCE POINT 6.79

Volume at EQUIVALENCE POINT 7.50

Answer these questions and explain why

1. What relationships exist at a half-way point for acids? For bases?
2. What relationship exists at the equivalence point?

Answer 1

1.After the equivalence point, the stoichiometric reaction has neutralized all the sample, and the pH depends on how much excess titrant has been added. After equivalence point, any excess strong base KOH determines the pH.

2.Equivalence point: point in titration at which the amount of titrant added is just enough to completely neutralize the analyte solution.