Input interpretation
oxygen
Chemical names and formulas
formula | O_2 name | oxygen IUPAC name | molecular oxygen alternate names | dioxygen | Freon 732 | molecular oxygen | oxygen gas | R-732 mass fractions | O (oxygen) 100%
Lewis structure
Draw the Lewis structure of oxygen. Start by drawing the overall structure of the molecule, ignoring potential double and triple bonds: Count the total valence electrons of the oxygen (n_O, val = 6) atoms: 2 n_O, val = 12 Calculate the number of electrons needed to completely fill the valence shells for oxygen (n_O, full = 8): 2 n_O, full = 16 Subtracting these two numbers shows that 16 - 12 = 4 bonding electrons are needed. Each bond has two electrons, so in addition to the 1 bond already present in the diagram add 1 bond. Identify the atoms that want additional bonds and the number of electrons remaining on each atom: Fill in the 1 bond by pairing electrons between adjacent highlighted atoms: Answer: | |
3D structure
3D structure
Basic properties
molar mass | 31.998 g/mol phase | gas (at STP) melting point | -218 °C boiling point | -183 °C density | 0.001429 g/cm^3 (at 0 °C) dielectric constant | 1
Gas properties (at STP)
density | 0.001429 g/cm^3 (at 0 °C) vapor density | 1.11 (relative to air) molar volume | 22390 cm^3/mol surface tension | 0.01347 N/m refractive index | 1.000271 dynamic viscosity | 2.055×10^-5 Pa s (at 25 °C)
Units
Thermodynamic properties
specific heat capacity c_p | gas | 0.9188 J/(g K) | liquid | 1.699 J/(g K) molar heat capacity c_p | gas | 29.4 J/(mol K) | liquid | 54.37 J/(mol K) specific free energy of formation Δ_fG° | gas | 7.241 kJ/g molar free energy of formation Δ_fG° | gas | 231.7 kJ/mol specific heat of formation Δ_fH° | gas | 0 kJ/g molar heat of formation Δ_fH° | gas | 0 kJ/mol specific entropy S° | gas | 6.407 J/(g K) molar entropy S° | gas | 205 J/(mol K) molar heat of vaporization | 6.8 kJ/mol | specific heat of vaporization | 0.2125 kJ/g | molar heat of fusion | 0.44 kJ/mol | specific heat of fusion | 0.014 kJ/g | critical temperature | 154.59 K | critical pressure | 5.043 MPa | (at STP)
Phase diagram
Phase diagram
Units
Chemical identifiers
CAS number | 7782-44-7 PubChem CID number | 977 PubChem SID number | 24857799 SMILES identifier | O=O InChI identifier | InChI=1/O2/c1-2 RTECS number | RS2060000 MDL number | MFCD00011434
NFPA label
NFPA label
NFPA health rating | 3 NFPA fire rating | 0 NFPA reactivity rating | 2 NFPA hazards | oxidizing agent
Toxicity properties
odor | odorless
RTECS classes | mutagen | reproductive effector | human data