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
$WO_3 \bullet (H_2O)$
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
$H_2O$ Water molecule 1 0.2 1 hydration main
Chemical functions
  Function Number
$R-OH$ 2
Chemical bonds
  Bond Number
$\geq\mid W-O$ 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 $g/cm^3$
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 $n_{\alpha}$
2.09
Refraction index $n_{\beta}$
2.24
Refraction index $n_{\gamma}$
2.26
Pure color
yellow
Diaphaneity
translucent to subtranslucent
Luster
earthy
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