These are the characteristics that apply:
- In a solution taste sour: which is consequence of the H+ concentration.
- Corrode metals: the H+ ion reacts with the metal producing a salt and water
-Produce hydronium ion in solution: as per the Bronsted - Lowry definition an acid is a substance that donates a proton, H+. This proton will react with H2O to form H3O+ (hydronium), as per this scheme:
HA + H2O --> A(-) + H3O(+)