Measuring PH with Red Cabbage

Measuring PH with Red Cabbage Experiment GIF

Lab Safety

Always wear eye protection during science experiments. Never handle sharp objects, open flames, chemicals, or other dangerous objects without adult permission and supervision.

I promise! Signed, ___________________________________

Red cabbage is red (well, purple) because of a chemical called anthocyanin. Anthocyanin has a special property that causes it to change colors in solutions with different PH levels.

This experiment is best suited for kids in grades 6 and up.

Procedure

  1. Step 1

    Using the cheese grater, grate some the red cabbage and place it into the bowl.

  2. Step 2

    Cover the cabbage with hot water from the faucet and let it sit for an hour. The liquid should turn dark purple or blue-purple.

  3. Step 3

    Once the water has cooled to a safe temperature, use the strainer to strain the cabbage-water mixture into another bowl.

  4. Step 4

    Once you've strained the solution, pour a small amount into three glasses.

  5. Step 5

    For the first PH test, cut a piece of the lemon and squeeze it into the first glass.

  6. Step 6

    For the second test, cut off a small piece of soap and stir it into the second glass.

  7. Step 7

    Now, compare both of these glasses to the third glass. Using the picture above, see if you can figure out the PH of each solution and which one is basic and which one is acidic. (Hint: a PH of 7 is neutral, anything below 7 is acidic, and anything above 7 is basic.)

Lab Safety

Always wear eye protection during science experiments. Never handle sharp objects, open flames, chemicals, or other dangerous objects without adult permission and supervision.


Comments


By submitting a comment, you promise that you have your parent or guardian's permission, are 13 or older, and agree to Experimonkey's Terms of Use.