Input interpretation
hydrogen iodide
Chemical names and formulas
formula | HI name | hydrogen iodide alternate names | anhydrous hydrogen iodide | anhydrous hydroiodic acid | iodane mass fractions | H (hydrogen) 0.788% | I (iodine) 99.2%
Lewis structure
Draw the Lewis structure of hydrogen iodide. Start by drawing the overall structure of the molecule: Count the total valence electrons of the hydrogen (n_H, val = 1) and iodine (n_I, val = 7) atoms: n_H, val + n_I, val = 8 Calculate the number of electrons needed to completely fill the valence shells for hydrogen (n_H, full = 2) and iodine (n_I, full = 8): n_H, full + n_I, full = 10 Subtracting these two numbers shows that 10 - 8 = 2 bonding electrons are needed. Each bond has two electrons, so the above diagram has all the necessary bonds. There is 1 bond and hence 2 bonding electrons in the diagram. Lastly, fill in the remaining unbonded electrons on each atom. In total, there remain 8 - 2 = 6 electrons left to draw: Answer: | |
3D structure
3D structure
Basic properties
molar mass | 127.912 g/mol phase | gas (at STP) melting point | -50.76 °C boiling point | -35.55 °C density | 0.005228 g/cm^3 (at 25 °C) solubility in water | very soluble dielectric constant | 1.002
Gas properties (at STP)
density | 0.005228 g/cm^3 (at 25 °C) molar volume | 24470 cm^3/mol refractive index | 1.466 dynamic viscosity | 0.001321 Pa s (at -39 °C)
Units
Liquid properties (-35.55 °C)
sound speed | 565.2 km/h (at 0 °C (degrees Celsius))
Units
Thermodynamic properties
specific heat capacity c_p | gas | 0.2283 J/(g K) molar heat capacity c_p | gas | 29.2 J/(mol K) specific free energy of formation Δ_fG° | gas | 0.01329 kJ/g molar free energy of formation Δ_fG° | gas | 1.7 kJ/mol specific heat of formation Δ_fH° | gas | 0.2072 kJ/g molar heat of formation Δ_fH° | gas | 26.5 kJ/mol molar heat of vaporization | 20 kJ/mol | specific heat of vaporization | 0.156 kJ/g | molar heat of fusion | 2.87 kJ/mol | specific heat of fusion | 0.0224 kJ/g | critical temperature | 424 K | critical pressure | 8.31 MPa | (at STP)
Chemical identifiers
CAS number | 10034-85-2 PubChem CID number | 24841 SMILES identifier | I InChI identifier | InChI=1/HI/h1H EU number | 233-109-9 Gmelin number | 814 RTECS number | MW3760000
NFPA label
NFPA label
NFPA health rating | 3 NFPA fire rating | 0 NFPA reactivity rating | 0
Ion equivalents
H^+ (hydrogen cation) | 1 I^- (iodide anion) | 1