Question

What is Ionisation equilibrium?

Answer 1

Ionization: Ionization is the process by which neutral molecules are converted into ions.

• Ionization equilibrium indicates the degree of ionization which is the yield of ionization refers to the number of neutral particles that are ionized into charged particles, such as those in gas or aqueous solution.
• The degree of ionization indicates the strength of the electrolyte. The higher the degree of ionization, the stronger the will be electrolyte.
• An equilibrium between the ionized particles and undissociated ions is known as ionic equilibrium.

Example: Ionization of weak acetic acid

The ionization of acetic acid can be represented as:

$\underset{\mathrm{Acetic}\mathrm{acid}}{{\mathrm{CH}}_3\mathrm{COOH}\left(\mathrm{aq}\right)}\rightleftharpoons \underset{\mathrm{Acetate}\mathrm{ion}}{{\mathrm{CH}}_3{\mathrm{COO}}^{-}\left(\mathrm{aq}\right)}+\underset{\mathrm{Hydrogen}\mathrm{ion}}{{\mathrm{H}}^{+}\left(\mathrm{aq}\right)}$

Applying the law of chemical equilibrium

$$\begin{gathered} {\mathrm{K}}_i=\frac{\left[{\mathrm{CH}}_3{\mathrm{COO}}^{-}\right]\left[{\mathrm{H}}^{+}\right]}{\left[{\mathrm{CH}}_3\mathrm{COOH}\right]} \\ {\mathrm{K}}_i=\mathrm{ionization}\mathrm{constant} \end{gathered}$$