Chapter 11, Problem 11.69P

a)

Interpretation Introduction

Interpretation:

The family of graphs for the titration of $\text{50}\text{.0}\text{of}\text{0}\text{.0200}\text{M}\text{HA}$ with $\text{0}\text{.100}\text{M}\text{B}$ has to be plotted.

Concept Introduction:

Titration of weak base with weak acid:

The both acid and base in the reaction are equally weak so, the equivalence point for the titration of weak acid and base has a pH around 7. There will not be any steep in the graph instead there is a point of inflection. That steep less in the graph is a factor that indicates that the difficult to do titration against weak acid to weak base.

Spreadsheet Equation for titration of diprotic with strong acid.

$\varphi =\frac{{\text{C}}_{\text{b}}{\text{V}}_{\text{b}}}{{\text{C}}_{\text{a}}{\text{V}}_{\text{a}}}\text{=}\frac{{\text{α}}_{{\text{A}}^{\text{-}}}\text{-}\frac{\left[{\text{H}}^{\text{+}}\right]\text{-}\left[{\text{OH}}^{\text{-}}\right]}{{\text{C}}_{\text{a}}}}{{\text{α}}_{{\text{BH}}^{\text{+}}}\text{+}\frac{\left[{\text{H}}^{\text{+}}\right]\text{-}\left[{\text{OH}}^{\text{-}}\right]}{{\text{C}}_{\text{b}}}}$

Where,

${\text{C}}_{\text{a}}$=initial concentration

${\text{C}}_b$=final concentration

${\text{V}}_{\text{a}}$=volume of the acid

${\text{V}}_{\text{b}}$= volume of the base

${\text{α}}_{{\text{BH}}^{\text{+}}}$=base dissociation constant.

${\text{α}}_{{\text{A}}^{\text{+}}}$=acid dissociation constant.

$\varphi$ =fraction way to equivalence point.

b)

Interpretation Introduction

Interpretation:

The acid-base reaction and equilibrium constant and pH of solution prepared from mixing $\text{212}\text{mL}\text{of}\text{0}\text{.200}\text{M}$ acetic acid with $\text{325}\text{mL}\text{of}\text{0}\text{.0500}\text{M}$ sodium benzoate has to be explained.

Concept Introduction:

Titration of weak base with weak acid:

The both acid and base in the reaction are equally weak so, the equivalence point for the titration of weak acid and base has a pH around 7. There will not be any steep in the graph instead there is a point of inflection. That steep less in the graph is a factor that indicates that the difficult to do titration against weak acid to weak base.

Spreadsheet Equation for titration of diprotic with strong acid.

$\varphi =\frac{{\text{C}}_{\text{b}}{\text{V}}_{\text{b}}}{{\text{C}}_{\text{a}}{\text{V}}_{\text{a}}}\text{=}\frac{{\text{α}}_{{\text{A}}^{\text{-}}}\text{-}\frac{\left[{\text{H}}^{\text{+}}\right]\text{-}\left[{\text{OH}}^{\text{-}}\right]}{{\text{C}}_{\text{a}}}}{{\text{α}}_{{\text{BH}}^{\text{+}}}\text{+}\frac{\left[{\text{H}}^{\text{+}}\right]\text{-}\left[{\text{OH}}^{\text{-}}\right]}{{\text{C}}_{\text{b}}}}$

Where,

${\text{C}}_{\text{a}}$=initial concentration

${\text{C}}_b$=final concentration

${\text{V}}_{\text{a}}$=volume of the acid

${\text{V}}_{\text{b}}$= volume of the base

${\text{α}}_{{\text{BH}}^{\text{+}}}$=base dissociation constant.

${\text{α}}_{{\text{A}}^{\text{+}}}$=acid dissociation constant.

$\varphi$ =fraction way to equivalence point.