Description
Tellurium oxide is a general term for the binary compounds of oxygen and tellurium, commonly known as tellurium oxide TeO and tellurium dioxide TeO2, tellurium pentoxide Te2O5 and tellurium trioxide TeO3. Among these four oxides, tellurium oxide is basic, tellurium dioxide is amphoteric, and tellurium pentoxide and tellurium trioxide are acidic. Tellurium oxide is a gray-black solid, and its presence indicates that tellurium is more metallic than sulfur and selenium. Tellurium dioxide is a non-volatile white solid with a relative density of 5.67, a melting point of 733°C, a boiling point of 1245°C, and is toxic! Difficult to dissolve in water, can dissolve in sodium hydroxide to generate sodium tellurite, with nitric acid acidification there are white flakes of tellurite H2TeO3 precipitation. Tellurium dioxide can be reduced to tellurium monomers by hydrogen when heated.
Chemical Properties
-60 mesh with 99.9% purity; two forms: yellowish orange α, and grayish β; αis a strong oxidant, e.g. reacting vigorously with Al, Sn, C, P and S [KIR83] [CER91]
Uses
Tellurium oxide is used in the preparation of tellurites, emission spectroscopy, and electronic component materials.It is also used as a brightener in electroplating solutions, as a catalyst for oil cracking, and as a colorant for ceramics and glass.
Synthesis
Tellurium trioxide, β-TeO3, is formed via thermal decomposition of Te(OH)6.
