Household Acids and Bases s1

HOUSEHOLD ACIDS AND BASES

Many household solutions contain acids or bases. Whether a substance is acidic or basic can be determined using indicators. Examples of indicators are litmus and red cabbage juice. The acidity or basicity of a solution can be expressed using the pH scale. Solutions with a pH below 7 are acidic and solutions with a pH above 7 are basic. A pH of exactly 7 indicates the solution is neither an acid or base but is neutral.

CAUTION: Ammonia is toxic and irritation to the eyes. Drain cleaner is corrosive and can cause tissue damage. EYE PROTECTION IS REQUIRED!

Procedure:

Each lab table has different solutions on it. Groups will rotate to each table and perform the following tests:

LITMUS TEST Use a stirring rod to transfer one drop of the solution onot a small piece of blue litmus paper. Record the result. Again, using a stirring rod, transfer one drop of the solution onto a piece of red litmus paper. Record the result.

RED CABBAGE JUICE INDICATOR Place one dropper full of the test solution into a test tube. Add one dropper full of red cabbage juice indicator into the same tube Record the result. Keep all of your red cabbage test tubes until the lab is complete. pH TEST Use a stirring rod to transfer on drop of the solution onto a small piece of pH paper. Compare the color of the paper to the chart provided. Record your results.

Sample data table:

Solution Blue litmus Red litmus Red cabbage juice pH Vinegar Coca cola Drain cleaner

QUESTIONS: (complete sentences!!)

1. Which of the solutions are acids? Which tests indicated that they were acids? 2. Which of the solutions are bases? How did you know? 3. Can red cabbage juice be used to determine the strength of acids and bases? Explain.