Chapter 11, Problem 11.73P

Interpretation Introduction

Interpretation:

The graph for the titration of tetrabasic base with strong acid, $\text{50}\text{.0}\text{mL}$ of $\text{0}\text{.0200}\text{M}\text{sodium}\text{pyrophosphate}\left({\text{Na}}_{\text{4}}{\text{P}}_{\text{2}}{\text{O}}_{\text{7}}\right)$ with $\text{0}\text{.100}\text{M}{\text{HClO}}_{\text{4}}$ has to be plotted.

Concept Introduction:-

Titration of tetrabasic base with strong acid:

When a strong acid is titrated against tetrabasic base, there is an equivalence or stoichiometric point, when an H⁺ is dissociated then there are multiple equivalence points. The equivalence point will occur when the moles of the strong acid added to same amount of the moles of weak base present. However, when a weak polyprotic acid is titrated. Therefore, the number of equivalence points depends on the number of H⁺ atoms that can be removed from the molecule.

Spreadsheet Equation for titration of titration of tetrabasic base with strong acid:

$\varphi \equiv \frac{{\text{C}}_{\text{a}}{\text{V}}_{\text{a}}}{{\text{C}}_{\text{b}}{\text{V}}_{\text{b}}}\text{=}\frac{{\text{α}}_{{\text{BH}}^{\text{+}}}{\text{+2α}}_{{\text{BH}}_{\text{2}}{}^{\text{2+}}}{\text{+3α}}_{{\text{BH}}_{\text{4}}{}^{\text{4+}}}{\text{+4α}}_{{\text{BH}}_{\text{4}}{}^{\text{4+}}}\text{+}\frac{\left[{\text{H}}^{\text{+}}\right]\text{-}\left[{\text{OH}}^{\text{-}}\right]}{{\text{C}}_{\text{b}}}}{\text{1-}\frac{\left[{\text{H}}^{\text{+}}\right]\text{-}\left[{\text{OH}}^{\text{-}}\right]}{{\text{C}}_{\text{a}}}}$

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

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

$\varphi$ =fraction way to equivalence point.