Chemical reactions

Reaction of cesium with acids

Cesium metal dissolves readily in dilute sulphuric acid forming Cs(I) ions and hydrogen, H2.

2 Cs(s) + H2SO4(aq) 2 Cs+(aq) + SO42−(aq) + H2(g)

Reaction of cesium with air

Cesium tarnishes slowly in air as it react with both oxygen and water in the air. If burned in air, the result is mainly formation of the orange cesium superoxide, CsO2.

Cs(s) + O2(g) CsO2(s) [orange]

Reaction of cesium with halogens

Cesium reacts rigorously with all the halogens forming the corresponding cesium halides.

2 Cs(s) + F2(g) 2 CsF(s)
2 Cs(s) + Cl2(g) 2 CeCl(s)
2 Cs(s) + Br2(g) 2 CeBr(s)
2 Cs(s) + I2(g) 2 CeI(s)

Reaction of cesium with hydrogen

Cesium reacts with hydrogen, forming cesium hydride [5].

2 Cs(s) + H2(g) 2 CsH(s)

Reaction of cesium with water

Cesium reacts violently with water, forming cesium hydroxide (CsOH) and hydrogen, H2.

2 Cs(s) + 2 H2O(l) 2 CsOH(aq) + H2(g)