Octane

A hydrocarbon, C8H18, 114.232 g/mol. Boiling point 125.62 °C, melting point -56.73 °C, as published.

verified recordOrganic — hydrocarbon9 measured properties

Identifiers

Molecular formula: C₈H₁₈
Molecular weight: 114.232 g/mol
Exact mass: 114.140851 g/mol
IUPAC name: octane
SMILES: CCCCCCCC
InChI: InChI=1S/C8H18/c1-3-5-7-8-6-4-2/h3-8H2,1-2H3
InChIKey: TVMXDCGIABBOFY-UHFFFAOYSA-N

Open in ReactionLens Use in reaction prediction

Measured properties

Published measurements, each with its source. Two readings of one property are both shown, in the units each used.

Boiling Point: 258.1 °F at 760 mmHg (USCG, 1999)measured · CAMEO Chemicals; 125.62 °Cmeasured · Hazardous Substances Data Bank (HSDB)
Melting Point: -70.2 °F (USCG, 1999)measured · CAMEO Chemicals; -56.73 °Cmeasured · Hazardous Substances Data Bank (HSDB)
Density: 0.703 at 68 °F (USCG, 1999) - Less dense than water; will floatmeasured · CAMEO Chemicals; 0.6986 g/cu cm at 25 °Cmeasured · Hazardous Substances Data Bank (HSDB)
Solubility: 7e-05 % at 77 °F (NIOSH, 2024)measured · CAMEO Chemicals; In water, 0.66 mg/L at 25 °Cmeasured · Hazardous Substances Data Bank (HSDB)
Vapor Pressure: 10 mmHg (NIOSH, 2024)measured · CAMEO Chemicals; 14.1 [mmHg]measured · Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
LogP: log Kow = 5.18measured · Hazardous Substances Data Bank (HSDB); 5.18measured · Human Metabolome Database (HMDB)
Flash Point: 56 °F (USCG, 1999)measured · CAMEO Chemicals; 56 °F (13 °C) (Closed cup)measured · Hazardous Substances Data Bank (HSDB)
Viscosity: 0.5151 cP at 25 °Cmeasured · Riddick, J.A., W.B. Bunger, Sakano T.K. Techniques of Chemistry 4th ed., Volume II. Organic Solvents. New York, NY: John Wiley and Sons., 1985., p. 116
Refractive Index: Index of refraction: 1.3944 at 25 °C/Dmeasured · Haynes, W.M. (ed.). CRC Handbook of Chemistry and Physics. 94th Edition. CRC Press LLC, Boca Raton: FL 2013-2014, p. 3-426; Index of refraction: 1.3974 at 20 °Cmeasured · Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present., p. V22: 537 (1997)

Calculated properties

Derived from the structure, not from a sample; kept apart from the measurements above.

Molecular weight: 114.23 g/molcalculated · reference compound database; Average mass of one molecule, from reference compound database.
Exact mass: 114.140850574 Dacalculated · reference compound database; Mass of the most common isotopic form.
XLogP3: 3.9calculated · reference compound database; Estimated oil/water partition, computed by reference compound database.
Polar surface area: 0 Å²calculated · reference compound database; Polar surface area as computed by reference compound database.
Complexity: 25calculated · reference compound database; A rough measure of how intricate the structure is.
H-bond donors: 0calculated · reference compound database
H-bond acceptors: 0calculated · reference compound database
logP: 3.3668calculated · chemistry engine; Estimated preference for oil over water. Higher means more oil-like.
Topological polar surface area: 0 Å²calculated · chemistry engine; Surface area from polar atoms; relates to how easily a molecule crosses membranes.
H-bond donors: 0calculated · chemistry engine; Atoms that can donate a hydrogen bond.
H-bond acceptors: 0calculated · chemistry engine; Atoms that can accept a hydrogen bond.
Rotatable bonds: 5calculated · chemistry engine; Single bonds the molecule can freely twist around.
Molar refractivity: 39.05 cm³/molcalculated · chemistry engine; Relates to the molecule's polarisability.
Fraction sp³ carbons: 1calculated · chemistry engine; Share of carbon atoms with tetrahedral bonding.
QED drug-likeness: 0.4806calculated · chemistry engine; Quantitative estimate of drug-likeness (0–1).

What it is made of

Elements

C Carbon8 atoms · 84.1% by mass
H Hydrogen18 atoms · 15.9% by mass

Percentages are of the molecular weight above, worked out the same way the molar mass calculator does it.

Structure

Heavy atoms, hydrogen excluded: 8
Total atoms, hydrogen included: 26
Rings: 0
Aromatic rings: 0
Stereocentres: 0
Formal charge: 0

The molecule in three dimensions

Rotate and inspect the atoms. Loaded only when you ask, so the page stays light.

The drawing above is a diagram of what is bonded to what. A molecule is not flat, and the model here is one low-energy shape generated from the connectivity — useful for seeing which groups can reach each other, and not a measured structure. A real sample is a population of conformations, interconverting.

Reactions it appears in

No documented reaction with a written procedure and a source involves Octane yet.

Other names for it

The systematic name on this record is octane.

The sources also call it n-octane, Oktan, Oktanen, Ottani, DTXSID0026882, X1RV0B2FJV, NSC-9822, DTXCID406882, CHEBI:17590, normal-Octane, RefChem:6664.

Structurally related

Nothing structurally close to Octane has a page here yet.

Seen alongside it in reaction records

Molecules that appear in the same recorded reactions as Octane. This says nothing about structure: most of them are the bases, solvents, ligands and catalysts the chemistry needed, and they are here because somebody put them in the same flask.

1,4-Cyclohexanedicarboxylic acid

used as a reactant

C₈H₁₂O₄, 172.18 g/mol.

Where these values came from

reference compound database356
compound record
chemistry engine
structure perception

compound record.

What this page does not claim

Identifiers are copied from the source record, measured values are reported as published, and calculated values are marked as calculated. Nothing here is a hazard, purity or handling assessment — how the library is checked.