Solid phase
Official name
Sulfur dioxide phase I
Secondary names
SO2-I ice
Type
Family
molecular solid
Class
polar molecular solid
Compound type
inorganic molecular solid
Chemical composition
Formula
$SO_2$
Chemical formula
SO2
Elemental formula
S O2
Isotope mixture type
terrestrial abundance
2.0
  Formula Name Family Number min-max Mole fraction Isotope mole fraction State Relevance
$SO_2$ Sulfur dioxide molecule 1 1.0 1 pure main
Chemical bonds
  Bond Number
$=S=O$ 2
Class
molecular solids with polar molecules (02)
Type
with polyatomic inorganic polar molecules (02.02)
Group
with halogens (02.02.02)
Phase name
Phase I
Phase type
crystalline
Crystal system
orthorhombic
Crystal class
pyramidal
Crystal class symbol
mm2 (C2v)
Crystal spacegroup
Aba2
Molar mass
64.0635971 $g/mol$
Density
1.98 (77K) $g/cm^3$
State NTP
gas
Phase transitions
Phase transition type Other phases Temperature - Pressure
triple point solid-liquid-gas liquid SO2, SO2 gas 197.64 +/- 0.05K K (16.7 +/- 0.1 mbar)
solid-solid from amorphous SO2 (irreversible) above ~70K
Refringence type
biaxial
Refraction index $n_{\alpha}$
~1.50
Pure color
colorless
Diaphaneity
transparent
Luster
vitreous
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