Solid phase
Official name
Water ice Ih
Secondary names
Ice Ih; Hexagonal ice; Frozen water; Water ice
CAS number
7732-18-5
Type
Family
molecular solid
Class
hydrogen bonded molecular solid
Compound type
inorganic molecular solid
Chemical composition
Formula
$H_2O$
Chemical formula
H2O
Elemental formula
H2 O
Isotope mixture type
terrestrial abundance
2.0
  Formula Name Family Number min-max Mole fraction Isotope mole fraction State Relevance
$H_2O$ Water molecule 1 1.0 1.0 pure main
Chemical functions
  Function Number
$R-OH$ 2
Chemical bonds
  Bond Number
$-O \dots H-$ 4
$-O-H$ 2
Oxides
Formula $H_{2}O$
Mass fraction (%) 1.0
Class
molecular solids with hydrogen bonded molecules (03)
Type
homomolecular H-bonded solids (03.01)
Group
H2O polymorphs (03.01.01)
Code
03.01.01.01
Equivalent liquid
Liquid water
Phase name
H2O Ih
Phase type
crystalline
Crystal system
hexagonal
Crystal class
dihexagonal-dipyramidal
Crystal class symbol
6/mmm (D6h)
Crystal spacegroup
P6(3)/mmc
Molar mass
18.0153 $g/mol$
Density
0.917 (273 K) - 0.928 (90 K) $g/cm^3$
State NTP
liquid
Phase transitions
Phase transition type Other phases Temperature - Pressure
triple point solid-liquid-gas liquid water, gas 273.16 K (611.66Pa)
solid-liquid liquid water 273.15 K (100 kPa)
solid-solid water ice Ic ~220-240 K (0-200 MPa)
Refringence type
uniaxial
Refringence sign
unknown
Birefringence
0.01
Refraction index $n_{\alpha}$
1.31
Refraction index $n_{\beta}$
1.33
Pure color
colorless
Color
light blue (when thick)
Diaphaneity
transparent
Luster
vitreous
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