Chapter 15, Problem 15.111QE

(a)

Interpretation Introduction

Interpretation:

The solution of $0.250M\text{ HBr}$ has to be classified as either strongly acidic, weakly acidic, neutral, weakly basic, and strongly basic and also determine $\text{pH}$ of solution.

Concept Introduction:

The formula to calculate $\text{pH}$ is given as follows:

  $\text{pH}=-\text{log}\left[{\text{H}}_3{\text{O}}^{+}\right]$

(b)

Interpretation Introduction

Interpretation:

The solution of $0.50M\text{ HF}$ has to be classified as either strongly acidic, weakly acidic, neutral, weakly basic, and strongly basic and also determine $\text{pH}$ of solution.

Concept Introduction:

The ionization of a hypothetical weak acid $\left(\text{HA}\right)$ is given as follows:

  $\text{HA}\left(\text{aq}\right)+{\text{H}}_{\text{2}}\text{O}\left(\text{l}\right)\rightleftharpoons {\text{A}}^{-}\left(\text{aq}\right)+{\text{H}}_3{\text{O}}^{+}\left(\text{aq}\right)$

(c)

Interpretation Introduction

Interpretation:

Solution of $0.020M\text{ Ba}{\left(\text{OH}\right)}_2$ has to be classified as either strongly acidic, weakly acidic, neutral, weakly basic, and strongly basic and also determine $\text{pH}$ of solution.

Concept Introduction:

Refer to part (a).

(d)

Interpretation Introduction

Interpretation:

Solution of $0.44M{\text{ NH}}_3$ has to be classified as either strongly acidic, weakly acidic, neutral, weakly basic, and strongly basic and also determine $\text{pH}$ of solution.

Concept Introduction:

The ionization of a hypothetical weak base is given as follows:

  $\text{B}\left(\text{aq}\right)+{\text{H}}_{\text{2}}\text{O}\left(\text{l}\right)\rightleftharpoons {\text{BH}}^{\text{+}}\left(\text{aq}\right)+{\text{OH}}^{-}\left(\text{aq}\right)$

The expression of $K_{\text{b}}$ is given as follows:

  $K_{\text{b}}=\frac{\left[{\text{BH}}^{+}\right]\left[{\text{OH}}^{-}\right]}{\left[\text{B}\right]}$

Here,

$\left[\text{B}\right]$ denotes the concentration of hypothetical weak base.

$\left[{\text{OH}}^{-}\right]$ denotes the concentration of ${\text{OH}}^{-}$ ions.

$\left[{\text{BH}}^{+}\right]$ denotes the concentration of ${\text{BH}}^{+}$ ions.

$K_{\text{b}}$ denotes ionization constant of weak base.