Introducing
Your new presentation assistant.
Refine, enhance, and tailor your content, source relevant images, and edit visuals quicker than ever before.
Trending searches
The Briggs-Rauscher Reaction
20
The Briggs-Rauscher Reaction
All the Interdependent Reactions Involved
The Simpler Explanation
What's Happening?
- The yellow colour generated in the Briggs-Rauscher reaction is due to an increase in the concentration of Iodine (I2).
- The blue colour is due to an increase in the concentration of a starch/iodine complex.
- The colourless condition is due to an increase in the concentration of Iodide ions(I-).
The "Scary" Explanation
The Slightly More In-depth Explanation
• The yellow colour is generated when iodide ions (I-) react with Hypoiodous acid (HOI) to form Iodine (I2).
• The blue colour occurs when Iodine reacts to an increase in Iodide ions (I-) in the presence of starch to form pentaiodide ions (I-5). This reaction consumes Iodine (I2) faster than it is produced, causing the concentration of pentaiodide ions (I-5) to decrease and increasing the concentration of iodide ions (I-) again.
• The increase in iodide ions (I-) leads to a colourless solution.
• At this stage, the iodide ions (I-) once again react with Hypoiodous acid (HOI) to form Iodine (I2) and the cycle begins again.
• The catalysts driving these (simplified) series of reactions are malonic acid and Iodate ions (IO3-).
• Once these are depleted, the oscillations decrease and finally reach a steady state where pentaiodide ions dominate, creating a blue colour.
Components of Reaction
Solution 3:
- Deionized water
- Manganese Sulfate in water (MnSO4) (aq)
- Soluble starch
- Malonic acid
Solution 1:
- 30% Concentrated Hydrogen Peroxide
- Deionized water
Solution 2:
- Potassium Iodate (KIO3)
- Hydrogen Sulfate (H2SO4)
- Deionized water
Stir plate!
The Briggs-Rauscher Reaction
The "Oscillating Clock" Reaction
By: Ariana A, Léal M, Jenna S, & Danté W.
References
Basch R, Castorani S, Seiders M. “An Investigation into the Briggs-Rauscher Reaction: Milestone #5.” (21 November 2003) Math 512 Project. http://www.math.udel.edu/~rossi/Math512/2003/br5.pdf
“Briggs-Rauscher Reaction—Yellow to Blue Switcheroo.” Chemistry Department Lecture Demonstrations (Kinetics). North Carolina State University.
http://ncsu.edu/project/chemistrydemos/Kinetics/BriggsRauscher.pdf
Farusi G. “The Briggs-Rauscher Reaction. “(2009) Science in School.org. 13:39-43.
http://www.scienceinschool.org/repository/docs/issue13_antioxidants_reaction.pdf