Rb2O

Rubidium oxide, with the chemical formula Rb2O, is an inorganic compound and one of the simple oxides of rubidium. It is typically encountered as a white, hygroscopic solid that readily absorbs moisture from the air.

The compound is highly reactive, especially with water. It reacts with water to form rubidium hydroxide and hydrogen gas: Rb2O + H2O → 2 RbOH. It also reacts with acids to give rubidium salts, and with carbon dioxide to form rubidium carbonate: Rb2O + CO2 → Rb2CO3. Because of its basic character and reactivity, Rb2O is primarily of interest as a reagent in inorganic synthesis and as a precursor to other rubidium compounds. It is usually handled under strictly dry, inert conditions and stored in moisture-tight containers, sometimes under mineral oil or in an inert atmosphere to prevent contact with air and moisture.

Preparation methods include direct oxidation of rubidium metal in oxygen, for example by burning rubidium in air or oxygen to form Rb2O, and dehydration of rubidium carbonate at elevated temperature to yield the oxide. In practice, the oxide is typically produced in controlled laboratory or industrial settings where moisture control is feasible.

Safety considerations are important: Rb2O is caustic and reacts violently with water, releasing heat and hydrogen gas. It must be handled with appropriate protective equipment and stored away from moisture and incompatible materials to minimize risk of ignition or caustic exposure.