What are the advantages and disadvantages of red cabbage juice indicator?

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trophyhunter1 eNotes educator| Certified Educator

To test pH, one can use pH paper or chemical indicators. Red cabbage juice changes color in the presence of an acid or a base and can be easily made at home. Anthocyanin, a pigment in the leaves of cabbage and other plants, is the reason for the color change. The cabbage is cut up and boiled and the cabbage juice is used as an indicator. Acidic solutions make the anthocyanin in cabbage juice turn reddish pink colors, while basic solutions turn the cabbage solution blue or green colors. Cabbage juice has its limitations. Depending on how dilute someone makes the cabbage juice solution, the color change for various pH levels may be lighter or darker for the same pH. In other words, it does not have a standard color range like pH paper, which is always the same with a predicted color change for a specific pH.