noun
monohydrate
Technical term in chemistry for a compound containing one molecule of water of crystallization.
この一水和物は加熱すると結晶水を失う。
This monohydrate loses its water of crystallization when heated.
Compound of 一水 (いっすい, 'one water') and 和物 (わぶつ, 'compound'), a calque from Western chemical nomenclature.