Solid phase
Official name
Tungstic acid
Secondary names
Tungstic(VI) acid; Dihydroxydioxotungsten; dihydroxy(dioxo)tungsten; Dihydrogen wolframate; Orthotungstic acid; Tungsten hydroxide oxide; Tungsten trioxide monohydrate; Tungstite (mineral)
CAS number
7783-03-1
Type
Family
covalent network solid
Class
sheet covalent network solid
Compound type
tungstate
Chemical composition
Formula
WO3∙(H2O)
Chemical formula
WO3•H2O
Elemental formula
W O4 H2
Isotope mixture type
terrestrial abundance
10.0
  Formula Name Family Number min-max Mole fraction Isotope mole fraction State Relevance
W Tungsten element 1 0.2 1 constituent element main
O Oxygen element 3 0.6 1 constituent element main
H2O Water molecule 1 0.2 1 hydration main
Chemical functions
  Function Number
R−OH 2
Chemical bonds
  Bond Number
≥∣W−O 6
−O−H 2
Class
molecular solids with hydrogen bonded molecules (03)
Type
polymolecular H-bonded solids with H2O (hydrates) (03.02)
Group
Mono-hydrates (03.02.02)
Phase type
crystalline
Crystal system
orthorhombic
Crystal class
dipyramidal
Crystal class symbol
mmm (D2h)
Crystal spacegroup
Pmna
Molar mass
249.85 g/mol
Density
5.59 g/cm3
State NTP
solid
Phase transitions
Phase transition type Other phases Temperature - Pressure
solid-liquid decomposition liquid 100°C (373K)
Refringence type
biaxial
Refringence sign
negative
Birefringence
0.17
Refraction index nα
2.09
Refraction index nβ
2.24
Refraction index nγ
2.26
Pure color
yellow
Diaphaneity
translucent to subtranslucent
Luster
earthy
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