Cesium sulfide

Cesium sulfide is an inorganic compound with the chemical formula Cs₂S. It is a white solid that is highly soluble in water and forms a variety of hydrates. Cesium sulfide is an important compound in the field of chemistry and has applications in various industrial processes.

Structure and Properties

Cesium sulfide is composed of cesium (Cs) and sulfur (S) atoms. In its solid form, it adopts a crystalline structure similar to that of other alkali metal sulfides. The compound is ionic, consisting of cesium cations (Cs⁺) and sulfide anions (S²⁻).

Physical Properties

• Molecular formula: Cs₂S
• Molar mass: 297.87 g/mol
• Appearance: White solid
• Density: 4.24 g/cm³
• Melting point: 510 °C
• Solubility in water: Highly soluble

Chemical Properties

Cesium sulfide reacts with water to form cesium hydroxide (CsOH) and hydrogen sulfide (H₂S), a reaction that is typical of sulfides:

\[ \text{Cs}_2\text{S} + \text{H}_2\text{O} \rightarrow 2\text{CsOH} + \text{H}_2\text{S} \]

This reaction is exothermic and releases hydrogen sulfide gas, which is toxic and has a characteristic rotten egg smell.

Preparation

Cesium sulfide can be prepared by the direct combination of cesium and sulfur at elevated temperatures:

\[ 2\text{Cs} + \text{S} \rightarrow \text{Cs}_2\text{S} \]

Alternatively, it can be synthesized by the reaction of cesium hydroxide with hydrogen sulfide:

\[ 2\text{CsOH} + \text{H}_2\text{S} \rightarrow \text{Cs}_2\text{S} + 2\text{H}_2\text{O} \]

Applications

Cesium sulfide is used in various applications, including:

• Chemical synthesis: As a source of sulfide ions in chemical reactions.
• Electronics: In the production of certain types of electronic devices.
• Research: As a reagent in laboratory research.

Safety and Handling

Cesium sulfide should be handled with care due to its reactivity with water and the release of hydrogen sulfide gas. Proper protective equipment, such as gloves and goggles, should be used when handling this compound.

Also see

• Cesium
• Sulfide
• Alkali metal
• Inorganic compound