Chapter 8, Problem 74P

Interpretation Introduction

Interpretation:

The pH of a solution after mixing 300 mL of 0.30 m TRIS in the base form with 250. mL of 0.15 m TRIS, tris (hydroxymethylaminomethane in the acetic acid form should be calculated.

Concept Introduction:

The pH of buffer solution is calculated using the following formula:

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

This is known as Henderson- Hasselbalch equation. Here, $p{K}_{\text{a}}$ is negative log of acid dissociation constant, $\left[{\text{A}}^{-}\right]$ is concentration of conjugate base and $\left[\text{HA}\right]$ is concentration of acid.