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Product 12826

By: The Flinn Staff

In the Kinetics of Dye Fading Chemistry Laboratory Kit, students analyze “fading” reactions by measuring the specific indicator's color. The results reveal the reaction rate depends on the concentration of the indicator.

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Product Details

The acid–base indicators phenolphthalein, crystal violet and bromphenol blue turn various bright colors in basic solutions. Surprisingly, these colors will eventually fade if the solution is too basic! In this technology-based experiment, students analyze the kinetics of these “fading” reactions by measuring the absorbance or intensity of the specific indicator’s color as a function of time. Graphing the results reveals how the rate of the fading reaction depends on the concentration of the indicator—1st order or 2nd order. Includes Teacher Notes, extensive background material and reproducible student handouts.

Complete for 30 students working in pairs. Spectrophotometer or colorimeter is required.

Correlation to Next Generation Science Standards (NGSS)

Science & Engineering Practices

Using mathematics and computational thinking
Planning and carrying out investigations
Obtaining, evaluation, and communicating information
Developing and using models
Analyzing and interpreting data

Disciplinary Core Ideas

HS-PS1.A: Structure and Properties of Matter
HS-PS1.B: Chemical Reactions
HS-PS4.A: Wave Properties
HS-PS4.B: Electromagnetic Radiation
HS-PS4.C: Information Technologies and Instrumentation

Crosscutting Concepts

Structure and function
Cause and effect
Energy and matter

Performance Expectations

HS-PS1-1: Use the periodic table as a model to predict the relative properties of elements based on the patterns of electrons in the outermost energy level of atoms.
HS-PS2-6: Communicate scientific and technical information about why the molecular-level structure is important in the functioning of designed materials.
HS-PS1-5: Apply scientific principles and evidence to provide an explanation about the effects of changing the temperature or concentration of the reacting particles on the rate at which a reaction occurs.
HS-PS1-6: Refine the design of a chemical system by specifying a change in conditions that would produce increased amounts of products at equilibrium.
HS-PS4-1: Use mathematical representations to support a claim regarding relationships among the frequency, wavelength, and speed of waves traveling in various media.