This is one of Aya’s most favorite experiments, maybe because it is really fun to mix liquids and watch them turn into different colors. Nowadays, when I ask her what an “acid” is, she immediately recalls the experiment and tells me, “It’s the one that makes the red cabbage juice turn red!” (Break muna sa mga seryosong usapan, I’m lagging behind with the experiments! This one was done many months ago actually.)
For this experiment, you’ll need the following:
1. red cabbage
Side note: Aya argued that the “red” cabbage is actually “purple.” Are we color blind or something? Kids. Sigh.
2. 2 jugs
5. hot water
6. test substances: vinegar, lemon juice, bicarbonate of soda, etc.
Explanation: Red cabbage contains a pigment molecule called flavin (an anthocyanin) which changes colors depending on the pH of the substance added to it. This makes it a good pH indicator, turning red when acid is added (e.g., vinegar, lemon juice, etc.) or dark blue when alkalis are added (e.g., bicarbonate of soda, antacid, etc.).
Kids and parents, try this at home!