Home Categories Organic Chemistry Isooctane
A4978112

Isooctane , StandardforGC,≥99.5%(GC) , 540-84-1

Synonym(s):
2,2,4-Trimethylpentane;2,2,4-Trimethylpentane, Isobutyltrimethylmethane, iso-Octane;Isooctane;TMP

CAS NO.:540-84-1

Empirical Formula: C8H18

Molecular Weight: 114.23

MDL number: MFCD00008943

EINECS: 208-759-1

Update time: 2022-07-08

PRODUCT Properties

Melting point: -107 °C
Boiling point: 98-99 °C(lit.)
Density  0.692 g/mL at 25 °C(lit.)
vapor density  3.9 (vs air)
vapor pressure  41 mm Hg ( 21 °C)
refractive index  n20/D 1.391(lit.)
Flash point: 18 °F
storage temp.  Store at +5°C to +30°C.
solubility  water: insoluble
form  Liquid
pka >14 (Schwarzenbach et al., 1993)
Specific Gravity 0.692 (20/4℃)
color  APHA: ≤10
Relative polarity -0.4
Odor Threshold 0.11ppm
explosive limit 1%(V)
Water Solubility  INSOLUBLE
FreezingPoint  -107.52℃
λmax λ: 205 nm Amax: 1.00
λ: 225 nm Amax: 0.10
λ: 254 nm Amax: 0.01
Merck  14,5193
BRN  1696876
Henry's Law Constant 3.23 at 25 °C (Mackay and Shiu, 1981)
Exposure limits ACGIH TLV: TWA for all isomers 300 ppm (adopted).
Dielectric constant 2.1(Ambient)
Stability: Stable. Highly flammable. Incompatible with oxidizing agents, reducing agents.
LogP 4.373 (est)
CAS DataBase Reference 540-84-1(CAS DataBase Reference)
NIST Chemistry Reference Pentane, 2,2,4-trimethyl-(540-84-1)
EPA Substance Registry System 2,2,4-Trimethylpentane (540-84-1)

Description and Uses

Isooctane is a flammable liquid isomer of octane. It is best known for defining the octane number to rate the antiknock quality of gasoline, which is related to engine performance.
Since 1930, many chemical processes, such as alkylation and polymerization, have been developed to increase the production of branched compounds in refi nery operations. High octane numbers in gasoline are those associated with the alkenes (olefins) and aromatics, especially akyl benzene compounds. For example, 2-pentene has a RON of 154. Benzene itself has a RON of 98, but 1,3,5-trimethylbenzene has a RON of 170. The highest octane numbers in gasoline are associated with cyclic alkenes, but these account for only a minute fraction of gasoline.

In determining octane numbers of fuels; in spectrophotometric analysis; as solvent and thinner.

Safety

Symbol(GHS) 
GHS02,GHS07,GHS08,GHS09
Signal word  Danger
Hazard statements  H225-H304-H315-H336-H410
Precautionary statements  P210-P273-P301+P310+P331-P302+P352
Hazard Codes  F,Xn,N
Risk Statements  11-38-50/53-65-67
Safety Statements  9-16-29-33-60-61-62
RIDADR  UN 1262 3/PG 2
WGK Germany  1
RTECS  SA3320000
Autoignition Temperature 745 °F
TSCA  Yes
HS Code  2901 10 00
HazardClass  3
PackingGroup  II
Hazardous Substances Data 540-84-1(Hazardous Substances Data)
Toxicity LD50 orally in Rabbit: > 2500 mg/kg

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