Key Concepts: Identifying Acids & Bases

Core Definitions

• Indicators: Chemicals that change color depending on pH (e.g., litmus, phenolphthalein).
• Litmus Test: Blue litmus turns red in acid; red litmus turns blue in base.
• Phenolphthalein: Colorless in acid, turns pink/magenta in base (pH > 8.2).
• pH Paper: Universal indicator paper that shows a range of colors for different pH values.