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Thionin - The Two-Faced Solution - Chemical Demonstration Kit

By: The Flinn Staff

Item #: AP8845

Price: $25.05

In Stock.

The Thonon the Two-Faced Solution Light-Activated Chemical Demonstration Kit is an activity enjoyed by students and instructors alike. Students study light-activated reactions and indicators. “Elegant” best describes this wonderful demo.

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This item can only be shipped to schools, museums and science centers

Product Details

“Elegant” best describes this wonderful demonstration. A large beaker containing a purple solution is placed on an overhead projector. Aluminum foil is placed under the beaker so only half the beaker will be exposed to direct light. Switch the overhead lamp on and in a matter of seconds, the side of the beaker exposed to the light turns colorless. The unexposed side remains purple. The intense light causes iron(II) to reduce thionin in an acidic solution. The thionin is photochemically reduced—a visible example of the conversion of light energy to chemical energy. Since the chemical solution can be used over and over again we have provided enough materials to prepare the solution three times. Both you and your students will enjoy this demonstration. Teacher Demonstration Notes included. Enough materials are included to perform the demonstration seven times. Concepts: Light-activated reactions, indicators. Time Required: 15 minutes Chemicals Provided: Thionin, sulfuric acid solution, iron(II) sulfate.


Materials Included in Kit: 
Iron(II) sulfate, 6 g
Sulfuric acid solution, 3 M, 30 mL
Thionin, 0.023 g

Correlation to Next Generation Science Standards (NGSS)

Science & Engineering Practices

Asking questions and defining problems
Developing and using models
Constructing explanations and designing solutions
Engaging in argument from evidence

Disciplinary Core Ideas

MS-PS1.A: Structure and Properties of Matter
MS-PS1.B: Chemical Reactions
MS-PS4.B: Electromagnetic Radiation
HS-PS1.A: Structure and Properties of Matter
HS-PS1.B: Chemical Reactions
HS-PS3.B: Conservation of Energy and Energy Transfer
HS-PS4.B: Electromagnetic Radiation

Crosscutting Concepts

Cause and effect
Systems and system models
Energy and matter
Stability and change

Performance Expectations

MS-PS1-2. Analyze and interpret data on the properties of substances before and after the substances interact to determine if a chemical reaction has occurred.
MS-PS4-2. Develop and use a model to describe that waves are reflected, absorbed, or transmitted through various materials.
HS-PS1-2. Construct and revise an explanation for the outcome of a simple chemical reaction based on the outermost electron states of atoms, trends in the periodic table, and knowledge of the patterns of chemical properties.
HS-PS1-4. Develop a model to illustrate that the release or absorption of energy from a chemical reaction system depends upon the changes in total bond energy.
HS-PS4-3. Evaluate the claims, evidence, and reasoning behind the idea that electromagnetic radiation can be described either by a wave model or a particle model, and that for some situations one model is more useful than the other.