Question: Which of the following are Arrhenius bases?

(a)${\mathbf{\text{H}}}_{\mathbf{\text{3}}}{\mathbf{\text{AsO}}}_{\mathbf{\text{4}}}$

(b)${\mathbf{\text{Ba(OH)}}}_{\mathbf{\text{2}}}$

(c)$\mathbf{\text{HClO}}$

(d)$\mathbf{\text{KOH}}$

An Arrhenius base is a substance that raises the concentration of the ${\mathbf{\text{OH}}}^{\mathbf{\text{-}}}$ion in an aqueous solution. Classic Arrhenius bases are ionic compounds containing the${\mathbf{\text{OH}}}^{\mathbf{\text{-}}}$ion

The reaction for${\text{H}}_{\text{3}}{\text{AsO}}_{\text{4}}$ is as follows –

${\text{H}}_{\text{3}}{\text{AsO}}_{\text{4}}\rightleftharpoons {\text{H}}^{\text{+}}{\text{+H}}_{\text{2}}{\text{AsO}}_{\text{4}}^{\text{-}}$

The dissociation${\text{H}}_{\text{3}}{\text{AsO}}_{\text{4}}$ of in water produced a${\text{H}}^{\text{+}}$ ion.

Therefore,${\text{H}}_{\text{3}}{\text{AsO}}_{\text{4}}$ is not an Arrhenius base.

The reaction for${\text{Ba(OH)}}_{\text{4}}$ is as follows –

${\text{Ba(OH)}}_{\text{4}}\rightleftharpoons {\text{Ba}}^{\text{2 +}}{\text{+ 2OH}}^{\text{-}}$

The dissociation of${\text{Ba(OH)}}_{\text{4}}$ in water produced${\text{OH}}^{\text{-}}$ ions.

Therefore,${\text{Ba(OH)}}_{\text{4}}$ is an Arrhenius base.

The reaction for$HClO$ is as follows –

$HClO\rightleftharpoons {\text{H}}^{\text{+}}{\text{+ ClO}}^{\text{-}}$

The dissociation of$HClO$ in water produced a${\text{H}}^{\text{+}}$ ion.

Therefore,$HClO$ is not an Arrhenius base.

The reaction for$\text{KOH}$ is as follows –

$\text{KOH}\rightleftharpoons {\text{K}}^{\text{+}}{\text{+ OH}}^{\text{-}}$

The dissociation of$\text{KOH}$in water produced a${\text{OH}}^{\text{-}}$ ion.

Therefore, $\text{KOH}$is an Arrhenius base.