Answer:
Two or more compounds are called structural isomers if they possess the same molecular formula but different structural formulas.
Explanation:
- The molecular formula of a compound shows the number of atoms of each element in a single molecule.
- In addition to showing the number of atoms, the structural formula of a molecule shows how the atoms are arranged in that molecule.
Two compounds are considered structural isomers if their molecular formulas are the same while they differ in their structural formulas.
For example, the molecular formula [tex]\mathrm{C_4H_{10}}[/tex] represents both butane and methylpropane. However, the two compounds differ in their structural formula. (See the structural formulas in the diagram attached.)
- Butane is a straight-chain alkane, whereas
- Methylpropane is branched.
Due to the difference in the structures of structural isomers, there's a good chance that they will show different chemical and physical properties. For example, the melting point of butane is higher than that of methylpropane. The straight-chain shape of butane allows its molecules to be stacked close to each other. That allows for greater intermolecular forces and, therefore, a higher melting point.
