Formula: C₈H₁₈

Relative Molar Mass: 114.2302 grams

Percent Composition by Mass:

Carbon-- 8(12.0 g)/114.2 g x 100 = 84.1% C
Hydrogen-- 18(1.0 g)/114.2 g x 100 = 15.8% H

Percent Composition by Number:

Carbon-- 8 carbon atoms/ 26 atoms x 100 = 30.8% C
Hydrogen-- 18 hydrogen atoms/ 26 atoms x 100 = 69.2% H

Type of bonding: covalent (non-metal to non-metal)

Octane is a hydrocarbon, meaning that its structure is entirely made up of carbon and hydrogen atoms. More specifically, octane is a saturated hydrocarbon, or alkane. An alkane is a hydrocarbon whose bonds are all single bonds to four other atoms. Octane also is a normal alkane because it forms a straight chain of atoms in a zig-zag pattern with the angle degree of its bonds being 109.5.

Octane has 18 structural isomers. A structural isomer is a molecule containing the same atoms but with a different structure because it contains different bonding. Octane isomers can have straight or branched chain isomers. Each structural isomer has its own individual properties (i.e. melting point, boiling point, etc.).