1. pH

2. pH—Scale to measure how acidic or basic a solution is 0-14 Pure water is 7 and neutral (not an acid or base) Acids—less than 7(lower number more acidic) Bases—greater than 7(higher number more basic)

3. Acids pH less than 7 Taste sour Reacts with metals (bubbles) Acid mixed with base = neutral

4. Bases Taste bitter (coffee) Feel slippery (soap) Base plus acid= neutral (antacid + stomach acid = neutral)

5. Neutral Neither acid nor base Pure water is 7

6. Litmus paper Has a special dye that changes colors in acids and bases

7. Phenolphthalein Used to test for bases Chemical indicator

8. pH paper Has a range of colors depending on pH of solution Compare color paper turns to color on vial