Tungsten pentoxide

Tungsten pentoxide (W₂O₅) was reported in early literature but proved to have the stoichiometry W₁₈O₄₉. Sometimes called mineral blue, it is a blue solid formed by the reaction of tungsten trioxide, WO₃, and tungsten metal at 700 °C.

There are a number of these unusual intermediate oxides formed from reacting metal and trioxide namely, W₂₀O₅₈, W₂₄O₇₀. W₁₈O₄₉ contains both octahedral and pentagonal bipyramidal co-ordination of the metal atoms by oxygen.

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