Key Concepts: Acid & Base Properties

Core Definitions

• Acid: A substance that produces H⁺ (hydrogen) ions in solution; tastes sour; pH below 7.
• Base: A substance that produces OH⁻ (hydroxide) ions in solution; tastes bitter, feels slippery; pH above 7.
• Arrhenius Definition: Acids produce H⁺ in water; bases produce OH⁻ in water.
• Brønsted-Lowry Definition: Acids are proton (H⁺) donors; bases are proton acceptors.