The condensed formula for pentane is CH3(CH2)3CH3 or CH3CH2CH2CH2CH3. A condensed formula is a method of describing the elements or molecules that comprise a compound. Straight lines, dashes and wedges, which typically represent the chemical bonds between atoms in the molecular structure of a compound, are omitted in a condensed formula.
Some compounds can form repeating sub-units of atoms or molecules in one large complex chain, which is especially true for organic compounds. This type of compound is any chemical substance that contains the element carbon.
When representing the molecular formula of complex organic compounds, writing down all the elements and molecules can become long and tedious. Hence, organic chemists developed several methods for illustrating or jotting down molecular structures. These techniques include the Kekule method, bond-line formula and condensed formula.
The Kekule or straight line structure uses a line to show the shared electrons in a chemical bond. The bond-line formula or zigzag structure uses zigzagging lines to indicate bonds. The condensed formula does not include bonding structure. The connectivity between the atoms or molecules in an organic compound is indicated by the order in which atoms and molecules are written down.
Pentane, which is a type of hydrocarbon, contains five carbon atoms bonded to 12 hydrogen atoms, and it is represented by the chemical formula C5H12. It forms three structural isomers, which are variations of how the carbon atoms are arranged in the molecular structure. These isomers include n-pentane, 2-methylbutane and 2,2-dimethylpropane.