A student is trying to determine if a solution is acidic or basic. She does not have any litmus paper. Which would she most likely use to get a reading on her solution?

Red cabbage juice contains pigments that change color depending on whether a solution is acidic or basic, so it can act as a natural indicator. Soap and vinegar are themselves basic and acidic substances, respectively, and aquarium water is not a standard indicator. The best choice is cabbage juice.

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