Illustrated Glossary of Organic Chemistry

Monohydrate: A substance containing one water molecule of hydration. The water of hydration is written after the main formula, separated with a dot.

CaSO₄		CaSO₄^.H₂O		CaSO₄^.2H₂O
Anhydrous calcium sulfate Lacks water of hydration		Calcium sulfate monohydrate Contains one water of hydration		Calcium sulfate dihydrate Contains two waters of hydration