Chapter 10, Problem 10.25P

(a)

Interpretation Introduction

Interpretation:

The value of ${\text{pK}}_{\text{a}}$ for the acid ${\text{BH}}^{\text{+}}$ has to be identified.

Concept introduction:

Henderson-Hassel Balch equation

$\begin{array}{l}\text{pH}\text{=}{\text{pK}}_{\text{1}}\text{+log}\frac{\left[{\text{HA}}^{\text{-}}\right]}{\left[{\text{H}}_{\text{2}}\text{A}\right]}\\ \text{pH}\text{=}{\text{pK}}_{\text{2}}\text{+log}\frac{\left[{\text{A}}^{\text{2-}}\right]}{\left[{\text{HA}}^{\text{-}}\right]}\end{array}$

The $\text{pH}$ of solution can be calculated as,

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

With the above equation, the negative logarithm of activity of Hydrogen ion can be measured.

(b)

Interpretation Introduction

Interpretation:

The $\text{pH}$ is ${\text{BH}}^{\text{+}}\text{=}\left[\text{B}\right]$ at given condition has to be identified.

Concept introduction:

Henderson-Hassel Balch equation

$\begin{array}{l}\text{pH}\text{=}{\text{pK}}_{\text{1}}\text{+log}\frac{\left[{\text{HA}}^{\text{-}}\right]}{\left[{\text{H}}_{\text{2}}\text{A}\right]}\\ \text{pH}\text{=}{\text{pK}}_{\text{2}}\text{+log}\frac{\left[{\text{A}}^{\text{2-}}\right]}{\left[{\text{HA}}^{\text{-}}\right]}\end{array}$

The $\text{pH}$ of solution can be calculated as,

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

With the above equation, the negative logarithm of activity of Hydrogen ion can be measured.

(c)

Interpretation Introduction

Interpretation:

The principal species at $\text{pH}\text{=}\text{7}\text{.00:}\text{B}\text{or}{\text{BH}}^{\text{+}}$ has to be explained.

(d)

Interpretation Introduction

Interpretation:

The quotient $\frac{\left[\text{B}\right]}{\left[{\text{BH}}^{\text{+}}\right]}\text{at}\text{pH}\text{12}\text{.00}$ has to be explained.