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C8H18

C8H18, commonly known as octane, is an organic compound consisting solely of carbon and hydrogen atoms. It is a saturated hydrocarbon belonging to the alkane series, with eight carbon atoms forming a straight or branched chain and eighteen hydrogen atoms attached to satisfy tetravalency. The molecular formula reflects its composition, and its structural formula can be represented as CH3(CH2)6CH3 for the normal (n‑octane) isomer. Due to the eight carbon atoms, C8H18 has 18 possible structural isomers, including n‑octane, iso‑octane (2,2,4‑trimethylpentane), and several other branched forms, each differing in physical properties such as boiling point and flame resistance.

Octane is a colorless, volatile liquid at standard temperature and pressure, with a boiling point near 125 °C

Industrial production of octane is achieved by catalytic reforming of petroleum fractions or by isomerization processes

and
a
density
of
about
0.70 g cm⁻³.
It
is
poorly
soluble
in
water
but
mixes
readily
with
most
organic
solvents.
The
compound
is
a
major
component
of
gasoline,
where
its
resistance
to
premature
ignition,
measured
by
the
octane
rating,
determines
engine
performance.
Iso‑octane
is
selected
as
the
reference
fuel
with
an
octane
number
of
100,
while
n‑octane
has
a
lower
rating,
reflecting
a
greater
tendency
to
knock.
that
increase
the
proportion
of
high‑octane
branched
isomers.
Beyond
fuel
applications,
C8H18
serves
as
a
solvent
in
laboratory
procedures,
a
standard
for
calibration
of
analytical
equipment,
and
a
feedstock
for
the
synthesis
of
fragrances,
polymers,
and
other
chemicals.
Safety
considerations
include
flammability,
inhalation
hazards,
and
potential
health
effects
of
prolonged
exposure,
requiring
proper
ventilation
and
protective
equipment
when
handling
the
substance.