Acid - Base Indicator Activity
Students will determine the effect of common acids and bases on a pH indicator (red cabbage solution).
- Well plate
- Sample solutions of lemon juice, diluted household ammonia, clear soda, diluted vinegar, baking soda solution, distilled water.
- pH indicator (red cabbage solution).
- (7) 50 ml beakers + pipettes
- The instructor places the sample solutions in small beakers. Each beaker is labeled with a number or letter.
- Place 15 drops of pH indicator in seven wells of the well plate.
- In the seven wells with pH indicator, add five drops of liquid from the labeled beakers. The 1st well gets drops from the first beaker, the 2nd well gets drops from the second beaker, etc.
- The last well will have nothing added - this is the experimental control.
- Be sure to keep track of which wells received which treatment.
- If possible use your sense of smell to identify the samples.
- Record in a data table: the beaker number/letter, odor, and the color reactions.
- Use a chart of showing the pH of common substances to identify the beaker solutions.
- Use the chart to estimate the likely pH of each beaker's contents.
|Beaker ID||Odor||Color||Probable Beaker solution||Inferred pH|
Make a generalized statement about how red cabbage juice reacts to an acid and a base.