Question

Write the formula for Gypsum.

Answer 1

• Gypsum is a white or grey coloured inorganic compound that is made up of hydrated Calcium and Sulphate ions.
• The reaction involved is shown below.
  $$\begin{gathered} {\mathrm{CaCO}}_3\left(\mathrm{aq}\right)+{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)\to {\mathrm{CaSO}}_4\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right) \\ \mathrm{Calcium}\mathrm{Sulphuric}\mathrm{Calcium}\mathrm{Water}\mathrm{Carbon} \\ \mathrm{carbonate}\mathrm{acid}\mathrm{sulphate}\mathrm{dioxide} \end{gathered}$$
• The chemical formula of Gypsum is Calcium sulphate dihydrate ${\mathbf{CaSO}}_{\mathbf{4}}\mathbf{.}\mathbf{2}{\mathbf{H}}_{\mathbf{2}}\mathbf{O}$.