The role water in showing the properties of acids

An acid will only show its acidic properties when it is dissolved in water.
acids
Presence of water
Molecules in acids will ionize to hydrogen ions
An acid will only show its acidic properties when it is dissolved in water (the presences of hydrogen ions)

Without the presence of water
Cannot ionize to hydrogen ions
No free moving hydrogen ions
Acids remain in the form of molecules

Example: Ethanoic acid, CH3COOH only exhibits acidic properties when water is present. It does not show acidic properties in pure dry liquid state or in dry propanone. In pure dry liquid state or in dry propanone, ethanoic acid, CH3COOH remains as covalent molecules. No hydrogen ions are present, thus it does not exhibit acidic properties. In aqueous state or when water is present, ethanoic acid, CH3COOH solution ionizes partially to produce free mobile hydrogen ions. Hence, it exhibits acidic properties. Water causes the molecules of CH3COOH to ionize partially to produce free mobile hydrogen ions that give rise to the acidic properties of ethanoic acid, CH3COOH.