|Home | Acids | Bases | pH scale | Fun Lab on Testing pH | Useful Links |


Testing pH Using Natural Indicators

Goals:

Materials:

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.
Grease pencil
small test tubes (9)
test tube rack

Procedures

  1. 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.
  2. Mark each test tube with the identity of the solution it will contain.
  3. Fill each test tube about halfway with the solution to be tested.
  4. 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.
  5. Observe and record the color of each solution in your data table.

Conclusions

  1. Compare your observations with the cabbage juice colors listed below. Record the relative pH values of each solution in your table.
  2. Classify which solutions were acidic and which were basic.

Cabbage Juice Data