What is the condensed structural formula of Octadecane?

The condensed structural formula of Octadecane is CH₃(CH₂)₁₆CH₃.

Octadecane is a straight-chain alkane, a saturated hydrocarbon consisting of 18 carbon atoms linked by single bonds. Its chemical formula is C₁₈H₃₈, which adheres to the general formula for alkanes, CnH2n+2, where n=18.

Understanding the Condensed Structural Formula

A condensed structural formula simplifies the representation of organic molecules by omitting most explicit bonds between atoms and showing groups of atoms together. For an unbranched alkane like octadecane, this typically means showing the methyl (CH₃) groups at each end of the carbon chain and consolidating the repeating methylene (CH₂) groups in the middle.

• The CH₃ at the beginning represents the first carbon atom, which is bonded to three hydrogen atoms and one other carbon atom.
• The (CH₂)₁₆ represents the sixteen methylene groups that make up the interior of the carbon chain. Each of these carbon atoms is bonded to two hydrogen atoms and two other carbon atoms.
• The final CH₃ represents the last carbon atom at the other end of the chain, also bonded to three hydrogen atoms.

Summing the atoms in CH₃(CH₂)₁₆CH₃:

• Carbon atoms: 1 (from first CH₃) + 16 (from (CH₂)₁₆) + 1 (from last CH₃) = 18 carbon atoms.
• Hydrogen atoms: 3 (from first CH₃) + (2 * 16) (from (CH₂)₁₆) + 3 (from last CH₃) = 3 + 32 + 3 = 38 hydrogen atoms.
  This matches the overall chemical formula of Octadecane, C₁₈H₃₈.

Key Characteristics of Octadecane

As a long-chain alkane, Octadecane exhibits typical properties of hydrocarbons. It is a straight-chain saturated hydrocarbon, meaning all carbon-carbon bonds are single bonds, and it contains the maximum number of hydrogen atoms possible for its carbon framework.

Here are some fundamental characteristics of Octadecane:

Octadecane, like other long-chain alkanes, is generally nonpolar and insoluble in water but soluble in organic solvents. It is often found in petroleum products and can be used in various applications, including as a component in waxes, lubricants, and as a phase-change material for thermal energy storage.