Explain the significance of the –COOH functional group in carboxylic acids.

The –COOH functional group is significant because it defines carboxylic acids and is responsible for their acidic properties. This group allows carboxylic acids to donate protons (H+) in solution, which is a key characteristic of acids.

This question tests the student's understanding of functional groups and their role in determining the properties of organic compounds. It encourages students to connect structure with chemical behavior. This response is aligned to Carboxylic acids because it explains recall the first four members of a homologous series of carboxylic acids as methanoic acid, ethanoic acid, propanoic acid and butanoic acid using the correct AQA GCSE Chemistry organic context. Keep molecular formula, structural formula, displayed formula, and general formula distinct. Do not confuse alkanes with alkenes, saturated with unsaturated, cracking with combustion, polymers with monomers, or hydrocarbons with oxygen-containing alcohols and carboxylic acids. When formulae are used, preserve the stored notation exactly and explain the GCSE chemistry idea in words rather than using unsupported displayed-formula diagrams.