Chapter 11, Problem 11.HE

Interpretation Introduction

Interpretation:

The size of the ${\text{A}}^{\text{-}}$ anion is $\text{450}\text{pm}$, a $\text{0}\text{.100}\text{M}$ solution of the weak acid HA was titrated with $\text{0}\text{.100}\text{M}\text{NaOH}$, using activity coefficients the ${\text{pK}}_{\text{a}}$ value has to be calculated.

Concept Introduction:

Henderson-Hassel Balch equation:

The equation which derives the pH as a measure of acidity in chemical and biological systems, and it is also uses for pH of the buffer solution and calculating the equilibrium pH in acid-base reactions.

${\text{pH=pK}}_{\text{a}}{\text{+log}}_{\text{10}}\left(\frac{\left[{\text{A}}^{\text{-}}\right]}{\left[\text{HA}\right]}\right)$

Where,

${\text{pK}}_{\text{a}}$ =acid dissociation constant.

$\left[{\text{A}}^{\text{-}}\right]$ =concentration of base

$\left[{\text{HA}}^{\text{-}}\right]$=concentration of conjugate acid.