Chapter 9, Problem 9.HE

Interpretation Introduction

Interpretation:

A suitable bases that would be used for preparation of buffer of $\text{pH=9}\text{.00}$ has to be found.

Concept Introduction:

Conjugate acid-base pair:

Consider acid $\text{HA}$ with its corresponding base ${\text{A}}^{\text{-}}$ they are collectively known as conjugate acid-base pair since they are associated with gain or loss of proton.

Conjugate base of weak acid is a weak base.

Conjugate acid of weak base is a weak acid.

$\text{pK}$

The negative logarithm of an equilibrium constant is called as $\text{pK}$.

The ${\text{pK}}_{\text{a}}$ of weak acid is the negative logarithm of ${\text{K}}_{\text{a}}$ and can be given as,

${\text{pK}}_{\text{a}}\text{=-log}{\text{K}}_{\text{a}}$

The value of acid dissociation constant ${\text{K}}_{\text{a}}$ decreases with increase in ${\text{pK}}_{\text{a}}$.