c
\(\mathop {Ba{{\left( {{H_2}P{O_2}} \right)}_2}}\limits^{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,2 + \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \)   \({H_2}PO_2^{ - 1}\)

ધારો કે \(P\) નો ઓ.આંક \(= X\)છે.

\(\begin{array}{l}
2 \times 1 + X + 3 \times  - 2 =  - 1\\
X - 2 =  - 1\\
X =  + 2 - 1 =  + 1
\end{array}\)