Chapter 16, Problem 16.42QP

Interpretation Introduction

Interpretation:

The ${\text{[H}}^{\text{+}}\text{]}$ and $\text{pH}$ of the rain drop in which the carbonic acid is the only acid with a concentration of $1.8\times {10}^{-5}M$ has to be determined

Concept Information:

Strong 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.

For example:

Consider ionization of $\text{HCl}$ (a strong acid)

0.10-M $\text{HCl}$ solution contains 0.10 M hydronium ions ${\text{[H}}_{\text{3}}{\text{O}}^{\text{+}}\text{]}$ in it, because all the $\text{HCl}$ molecules ionizes.

At equilibrium (after the completion of ionization), the concentration of $\text{[HCl]}$ will be zero since no $\text{HCl}$ molecules remains after ionization.

The concentration after ionization will be as follows,

$\text{[HCl]}$= 0M

${\text{[H}}_{\text{3}}{\text{O}}^{\text{+}}\text{]}$ = 0.10 M

${\text{[Cl}}^{\text{-}}\text{]}$=0.1 M

$\text{pH}$ 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.

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

To Determine: The ${\text{[H}}^{\text{+}}\text{]}$ and $\text{pH}$ of the rain drop in which the carbonic acid is the only acid with a concentration of $1.8\times {10}^{-5}M$