Explore the pH scale — acids, bases, indicators, and buffer solutions
pH = −log[H⁺] measures how acidic or basic a solution is. pH < 7 = acidic (more H⁺ ions), pH = 7 = neutral, pH > 7 = basic (more OH⁻ ions). Each pH unit represents a 10× change in ion concentration. pH + pOH = 14. Common acids: HCl, H₂SO₄, citric acid. Common bases: NaOH, NH₃, Ca(OH)₂.