07. EQUILIBRIUM (IONIC) (HM)
Explanation:
$\begin{gathered}
I\,\,step \,\,\,\, {H_3}P{O_4} \rightleftharpoons {H^ + } + {H_2}PO_4^ - \hfill \\
II\,\,step \,\,\,\, {H_2}PO_{_4}^ - \rightleftharpoons {H^ + } + HPO_4^{ - - } \hfill \\
III\,\,step \,\,\,\, HPO_4^{ - - } \rightleftharpoons {H^ + } + PO_4^{ - - - } \hfill \\
\end{gathered}$
