Acids | Bases
| pH scale | Fun
Lab on Testing pH | Useful Links |
Testing pH Using Natural Indicators
concentnrated red cabbage juice in a dropper bottle
labeled bottles containing : household ammonia, baking soda solution, soap solution, hydrochloric acid solution, white vinegar, colorless carbonated soft drink, distilled water, and drain cleaner solution.
small test tubes (9)
test tube rack
- Design a data table in which you record the names of the solutions to be tested, the colors caused by the cabbage juice indicator, and the relative pH values of the solutions.
- Mark each test tube with the identity of the solution it will contain.
- Fill each test tube about halfway with the solution to be tested.
- Add ten drops of the cabbage juice indicator to each of the solutions to be tested. Gently wiggle the test tube so the cabbage juice gets mixed with the solution.
- Observe and record the color of each solution in your data table.
- Compare your observations with the cabbage juice colors listed below. Record the relative pH values of each solution in your table.
- Classify which solutions were acidic and which were basic.
Cabbage Juice Data
- bright red = strong acid
- red=medium acid
- reddish-purple=weak acid
- blue-green=weak base
- green=medium base
- yellow=strong base