Chapter 16.3, Problem 2PE

Interpretation Introduction

Interpretation:

From the given $\text{pH}$ of certain orange juice, the ${\text{H}}^{\text{+}}$ ion concentration has to be calculated.

Concept Introduction:

$\text{pH}$ is the negative logarithm of concentration of ${\text{H}}^{\text{+}}$ ion in a solution.

It can be expressed as

$\text{pH}\text{=}-\log \left[{\text{H}}^{\text{+}}\right]$

From the value of $\text{pH}$, a given solution can be determined as acidic, basic or neutral as shown below:

  $\begin{array}{l}\text{pH}>7\Rightarrow \text{acidic}\\ \text{pH}<7\Rightarrow \text{basic}\\ \text{pH}=7\Rightarrow \text{neutral}\end{array}$

If the value of $\text{pH}$ has been given then the concentration of ${\text{H}}^{\text{+}}$ ion can be calculated as follows:

  $\begin{array}{l}\text{pH}\text{=}-{\log }_{10}\left[{\text{H}}^{\text{+}}\right]\\ \left[{\text{H}}^{\text{+}}\right]={10}^{\text{-pH}}\end{array}$

In the $\text{pH}$ calculation, the hydrogen ion concentration has the unit of $\text{mol/L}$ which is known as $\text{Molarity}\text{.}$  It can be represented as $\text{M}$.