Names | |
---|---|
Preferred IUPAC name
Heptane[2] | |
Other names
Septane[1]
| |
Identifiers | |
3D model (JSmol)
|
|
1730763 | |
ChEBI | |
ChEMBL | |
ChemSpider | |
EC Number |
|
49760 | |
MeSH | n-heptane |
PubChem CID
|
|
RTECS number |
|
UNII | |
UN number | 1206 |
| |
| |
Properties | |
C7H16 | |
Molar mass | 100.205 g·mol−1 |
Appearance | Colourless liquid |
Odor | Petrolic |
Density | 0.6795 g cm−3[3] |
Melting point | −90.549[3] °C (−130.988 °F; 182.601 K) |
Boiling point | 98.38[3] °C (209.08 °F; 371.53 K) |
0.0003% (20 °C)[4] | |
log P | 4.274 |
Vapor pressure | 5.33 kPa (at 20.0 °C) |
Henry's law
constant (kH) |
12 nmol Pa−1 kg−1 |
−85.24·10−6 cm3/mol | |
Refractive index (nD)
|
1.3855[3] |
Viscosity | 0.389 mPa·s[5] |
0.0 D | |
Thermochemistry | |
Heat capacity (C)
|
224.64 J K−1 mol−1 |
Std molar
entropy (S⦵298) |
328.57 J K−1 mol−1 |
Std enthalpy of
formation (ΔfH⦵298) |
−225.2 – −223.6 kJ mol−1 |
Std enthalpy of
combustion (ΔcH⦵298) |
−4.825 – −4.809 MJ mol−1 |
Hazards | |
GHS labelling: | |
Danger | |
H225, H304, H315, H336, H410 | |
P210, P261, P273, P301+P310, P331 | |
NFPA 704 (fire diamond) | |
Flash point | −4.0 °C (24.8 °F; 269.1 K) |
223.0 °C (433.4 °F; 496.1 K) | |
Explosive limits | 1.05–6.7% |
Lethal dose or concentration (LD, LC): | |
LC50 (median concentration)
|
17,986 ppm (mouse, 2 hr)[6] |
LCLo (lowest published)
|
16,000 ppm (human) 15,000 ppm (mouse, 30 min)[6] |
NIOSH (US health exposure limits): | |
PEL (Permissible)
|
TWA 500 ppm (2000 mg/m3)[4] |
REL (Recommended)
|
TWA 85 ppm (350 mg/m3) C 440 ppm (1800 mg/m3) [15-minute][4] |
IDLH (Immediate danger)
|
750 ppm[4] |
Related compounds | |
Related alkanes
|
|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|
Heptane or n-heptane is the straight-chain alkane with the chemical formula H3C(CH2)5CH3 or C7H16. When used as a test fuel component in anti-knock test engines, a 100% heptane fuel is the zero point of the octane rating scale (the 100 point is 100% iso-octane). Octane number equates to the anti-knock qualities of a comparison mixture of heptane and iso-octane which is expressed as the percentage of iso-octane in heptane, and is listed on pumps for gasoline (petrol) dispensed globally.