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?

Cabbage juice contains pigments that change color depending on whether a solution is acidic or basic, so it can act as a natural indicator. Vinegar is acidic, soap is basic, and aquarium water may be close to neutral; none of those is as useful for testing an unknown solution as cabbage juice.

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