Question

Plaster of Paris should be stored in a moisture-proof container. Explain why?

Explain why plaster of Paris should be stored in a moisture-proof container.

Answer 1

The Plaster of Paris should be stored in a moisture-proof container, as it absorbs moisture and turns into a hard substance (gypsum), as shown in the following chemical equation.

\[\ce{\underset{Plaster of Paris}{CaSO4 * 1/2 H2O} + 3/2 H2O -> \underset{Gypsum}{CaSO4 * 2H2O}}\]