GIPHOTOSTOCK / SCIENCE PHOTO LIBRARY GIPHOTOSTOCK / SCIENCE PHOTO LIBRARY
Red cabbage juice indicator. Red cabbage juice indicator solution was added to several test tubes containing solutions with varying pH values, left to right: 1 through 13 in steps of 1. Hydrochloric acid of varying concentrations was used to prepare acidic solutions (pH<7), sodium hydroxide of varying concentrations was used to prepare alkaline solutions (pH>7), and neutral buffer solution was used for pH=7.
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