The characteristics that most accurately describe an acid are:
- Produces hydronium ions when it dissolves in water - This is a defining property of acids.
- Corrosive - Many acids can be corrosive to materials and living tissues.
- Sour tasting - This is a common characteristic of many acids (e.g., citric acid in lemons).
- Sting eyes and skin - Many acids can cause irritation and a stinging sensation upon contact.
The characteristics "Sweet tasting" and "Produces hydroxide ions when it dissolves in water" do not describe acids; the latter describes bases.