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解説
三酸化テルル：TeO3(175.60)．α-TeO3はオルトテルル酸Te(OH)6を360 ℃ 以上(赤熱以下)で加熱脱水して得られる．橙色の粉末．密度5.075 g cm－3(15 ℃)．200 ℃ で青変し，400 ℃ 以上で二酸化テルルと酸素に分解する．冷水，希アルカリには難溶であるが，熱水には溶けてふたたびオルトテルル酸となる．強塩基水溶液には溶けてテルル酸イオンを生じる．熱塩酸には強酸化剤としてはたらき，塩素を放って二酸化テルルと四塩化テルルになる．β-TeO3はオルトテルル酸Te(OH)6を長時間加熱脱水すると灰色の結晶性粉末として得られる．密度6.21 g cm－3．濃酸，濃アルカリ水溶液に不溶．400 ℃ 以上で二酸化テルルと酸素に分解する．
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説明
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.
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化学的特性
-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]
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使用
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.
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合成
Tellurium trioxide, β-TeO3, is formed via thermal decomposition of Te(OH)6.
