Chapter 16, Problem 16.13QP

Interpretation Introduction

Interpretation:

From the given $\text{pH}$, the acidity has to be predicted with reason.  Whether the $\text{pH}$ of a solution be zero or negative has to be discussed.

Concept Introduction:

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

It can be expressed as

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

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

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

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

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

A given solution can be determined as acidic, basic or neutral based on the ${\text{H}}^{\text{+}}$ ion concentration.

  $\begin{array}{l}\left[{\text{H}}^{\text{+}}\right]>1.0\times {10}^{-7}\text{M}\Rightarrow \text{acidic}\\ \left[{\text{H}}^{\text{+}}\right]<1.0\times {10}^{-7}\text{M}\Rightarrow \text{basic}\\ \left[{\text{H}}^{\text{+}}\right]=1.0\times {10}^{-7}\text{M}\Rightarrow \text{neutral}\end{array}$