Chapter 16, Problem 16.88QP

Interpretation Introduction

Interpretation:

The pH of a 0.0642-M solution of a monoprotic acid is 3.86.  Is this a strong acid has to be explained.

Concept Information:

Strong acids and weak acids:

In strong acids, the ionization of acid is complete.  This implies that the concentration of the hydrogen ion or hydronium ion will be equal to the initial concentration of the acid at equilibrium.

The ionization in weak acid is limited to some extent.  Weak acids does not undergo complete ionization.

The strong and weak acid can be classified based on the following:

• strong acids have low $\text{pH}$ value whereas weak acids have high $\text{pH}$ value
• When the $K_a$ is large, it indicates strong acid
• When the $K_a$ is small, it indicates weak acid
• If bond strength decreases, acid strength increases

$\text{pH}$ 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.

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

To Explain: whether the given acid with pH 3.86 is a strong acid or not