Question

What is the chemical formula of calcium hydroxide?

Answer 1

The chemical formula of calcium hydroxide is $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$.

$$\begin{gathered} \mathrm{The}\mathrm{valency}\mathrm{of}\mathrm{calcium}\left(\mathrm{Ca}\right)\mathrm{is}+2. \\ \mathrm{The}\mathrm{valency}\mathrm{of}\mathrm{hydroxide}\mathrm{ion}\left({\mathrm{OH}}^{-}\right)\mathrm{is}-1. \\ {\mathrm{Ca}}^{+2}{\mathrm{OH}}^{-1} \\ \mathrm{On}\mathrm{criss}\mathrm{crossing}\mathrm{the}\mathrm{valencies}\mathrm{of}\mathrm{calcium}\mathrm{and}\mathrm{hydroxide}\mathrm{ion}\mathrm{we}\mathrm{get}, \\ \mathrm{Ca}{\left(\mathrm{OH}\right)}_2 \end{gathered}$$