Formulas and Functional Groups | Chemistry for Grade 11 (IGCSE) PDF Download

Displayed Formulae

• Organic Chemistry involves examining the arrangement, properties, and reactions of carbon-based compounds.
• Carbon-containing compounds are categorized as organic compounds.
• Substances like metal carbonates, carbon dioxide, and carbon monoxide are not classified as organic compounds.
• Many structures you draw in organic chemistry are hydrocarbons, compounds made of hydrogen and carbon.
• Hydrocarbons exclusively consist of hydrogen and carbon atoms.
• Organic compounds can be depicted in various forms, such as Displayed Formulae, General Formulae, and Structural Formulae.
• The displayed formula illustrates the spatial arrangement of atoms and bonds within a molecule.
• For example:
  
• The displayed formula provides vital information about the compound:
  • It has 5 carbon atoms
  • It has 12 hydrogen atoms
  • It consists of only single bonds

Structural Formulae

• In structural formulae, the emphasis is on providing enough information for clarity while omitting most covalent bonds.
• Important bonds like double and triple bonds are always depicted.
• Identical groups are often grouped together within brackets for simplification.
• Side groups are represented using brackets.
• Straight chain alkanes are typically illustrated in a specific format.
  

Structural Isomers

• Structural isomers possess the same molecular formula but differ in their structural arrangements.
• The molecular formula indicates the precise number of atoms for each element in a compound.
• Compounds sharing the same molecular formula can exhibit distinct structural formulae due to varying spatial atom arrangements.
• Below are two instances highlighting structural isomerism: