NaOHH2O

NaOHH2O is a nonstandard way some sources use to refer to the hydrated form of sodium hydroxide, specifically sodium hydroxide monohydrate, with the conventional formula NaOH·H2O. In standard nomenclature, it is called sodium hydroxide monohydrate. This compound is a hydrated solid produced when anhydrous sodium hydroxide absorbs water from the environment or is crystallized from an aqueous NaOH solution.

In terms of structure and properties, NaOH·H2O consists of the same ionic Na+ and OH− framework as anhydrous NaOH, with one water molecule associated per NaOH unit. The solid is highly hygroscopic and readily absorbs moisture from the air, often deliquescing in humid conditions. It is strongly basic and caustic, and, like other sodium hydroxide derivatives, reacts exothermically with acids and organic materials. Upon heating, the hydrate can decompose, releasing water and leaving behind anhydrous sodium hydroxide.

Formation and occurrence are typically limited to laboratory or niche preparative contexts. It can be produced by careful crystallization from NaOH solutions or by controlled hydration of solid NaOH under specific conditions. In practice, sodium hydroxide is usually encountered as the anhydrous solid or, more commonly, as an aqueous solution, because the hydrated form is less stable and less widely used industrially.

Safety and handling note that NaOH and its hydrates are highly caustic and can cause severe burns. They should be handled with appropriate personal protective equipment, stored in sealed containers, and kept away from moisture sources to prevent hazardous reactions and degradation.