Chapter 6, Problem 6D.15E

(a)

Interpretation Introduction

Interpretation:

The $\text{pH}$ of 0.19 M aqueous ammonium chloride has to be calculated.

pH definition:

The concentration of hydrogen ion is measured using $\text{pH}$ scale.  The acidity of aqueous solution is expressed by $\text{pH}$ scale.

The $\text{pH}$ of a solution is defined as the negative base -10 logarithm of the hydrogen or hydronium ion concentration.

  $\text{pH}\text{=}{\text{-log[H}}_{\text{3}}{\text{O}}^{\text{+}}\text{]}$

On rearranging, the concentration of hydrogen ion ${\text{[H}}^{+}\text{]}$ can be calculated using pH as follows,

  ${\text{[H}}^{+}\text{]}\text{=}{\text{10}}^{\text{-pH}}$

(b)

Interpretation Introduction

Interpretation:

The $\text{pH}$ of 0.055 M aqueous ${\text{AlCl}}_{\text{3}}$ has to be calculated.

Concept introduction:

Refer to part (a).