Chapter 15, Problem 15.125QE

(a)

Interpretation Introduction

Interpretation:

$\text{pH}$ value of $0.25M\text{ HF}$ has to be calculated.

Concept Introduction:

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

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

(a)

Interpretation Introduction

Interpretation:

$\text{pH}$ value of $0.25M\text{ KF}$ has to be calculated.

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 ${\text{K}}_{\text{b}}$ 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.