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Natural Indicators—Acids, Bases and the pH Scale—Guided-Inquiry Kit

By: The Flinn Staff

Item #: AP6442

Price: $62.70

The Natural Indicators Chemistry Guided-Inquiry Laboratory Kit allows students to explore the origin of acid–base indicators. Students extract natural indicators and construct a pH color chart to find the pH values of unknown solutions.

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Product Details

Roses are red, violets are blue—or are they? Red roses, as well as many other flowers and fruits, contain natural indicators that are sensitive to acids and bases. The color of a natural acid–base indicator depends on pH. In this activity, the pH scale comes to life in living color as students explore the origin of acid–base indicators in nature. Students extract natural indicators from dried flowers, fruit juices or herbal teas. They then design a procedure to construct a pH color chart for their natural indicator and use the results to analyze the pH values of unknown solutions. Kit includes four natural indicator sources, a set of buffer capsules for the preparation of pH 2–12 standards, four unknowns and synthetic indicators for comparison. Indicator choices include red roses and hibiscus—your chemistry lab will never smell so good! Also includes reproducible student handouts, detailed background information, complete Teacher Notes with sample data and answers to questions and all necessary chemicals and consumable supplies.

Complete for 30 students working in pairs.