Chapter 16, Problem 16.41QE

Interpretation Introduction

Interpretation:

The volume of $\text{0}\text{.500 M HF}$ that is required to add to $\text{750 mL of 0}\text{.200 M}$ sodium fluoride to prepare a $\text{pH 3}\text{.95}$ buffer has to be calculated.

Concept introduction:

The pH of solution is calculated by using Henderson – Hasselbalch equation,

  $\text{pH = pKa + log }\left(\frac{\left[\text{Base}\right]}{\left[\text{Acid}\right]}\right)$

  ${\text{pK}}_{\text{a}}\text{ = -log}\left[{\text{K}}_{\text{a}}\right]$

A solution may be acidic and basic depends on relative strength of anions as an acid or base. Anions and cations can be acidic, basic and netural. Acidic have $\text{pH < 7}$, basic have $\text{pH > 7}$ and netural have $\text{pH=7}$.