UW-Madison Demonstration Lab
UW-Madison Department of Chemistry

Kinetics- CMW Two Stage Clock Reaction

Brigg-Rauscher Reaction

Burning Rate Depends on Oxygen Concentration

Chemical Genie in a Bottle

Iodine Clock Reaction

Kinetics of Crystal Violet

Kinetics of Decomposition of Hydrogen Peroxide by Permanganate

Kinetics of Oxidation of Iodide Ion by Peroxide

Light Sticks

Reaction Rate Depends on Particle Size

Visible Reactive Intermediate

Autocatalysis of Oxalate Ion with Permanganate

Catalytic Combustor

Catalytic Decomposition of Hydrogen Peroxide

Elephant’s Toothpaste

Explosions of Lycopodium and Other Powders

Medicine Cabinet Kinetics

Old Nassau: The Landolt Reaction with Mercury Indicator

Traveling Waves of Color

Catalytic Oxidation of Ammonia

Ignition of Hydrogen on a Platinum Catalyst

Slow Decolorization of Permanganate by Ethanol

Temperature Effect on Reaction Rate

CMW Two Stage Clock Reaction

An Orange Clock Reaction

The Reaction Between Oxalate Ion With Permanganate

CMW Two Stage Clock Reaction

Desciption: Equal volumes of three solutions, one clear and pale blue, two clear and colorless, are added and quickly mixed. After a brief induction period, the solution turns a bright orange. In several more seconds, the solution changes color again to a deep blue/black.

KIO3(aq)+ Na2S2O5(aq) → I–(aq)+ 2SO4-2(aq) + 2Na+(aq) + K+(aq)

IO3–(aq) + 8I–(aq) + 6H+(aq) → 3I3–(aq) + 3H2O(l)

HgCl2(aq) + 2I–(aq) ↔ HgI2(s)

2I3–(aq) + Starch ↔ blue starch-I5–(aq) + I–(aq)

Source: Dr. Chad M. Wilkinson, UW Madison Personal Consult (2012)

Shakhashiri, B. Z., Chemical Demonstrations: A Handbook for Teachers of Chemistry vol 4 (1993) pp26-30

Year: 2012, 1993   Vol: 4   Page: 26 -30

Keywords: Clock Reaction, Precipitate, Complexation, Starch, Kinetics

Rating:

Hazard: Medium

  • Acute toxicity hazard
  • Aquatic hazard
  • Flammability hazard
  • Reproductive hazard
  • Germ cell mutagenicity
  • Respiratory hazard
  • Serious eye damage
  • Skin corrosion hazard

Effectiveness: Good

  • Good connection to course material
  • Results are clearly observable without guidance
  • Time to results is low
  • High reliability

Difficulty: Medium

  • Prior training recommended
  • Procedures with some intermediate steps to results
  • Adding reagents in concerts or timed

Safety Precautions:

  • Eye protection required
  • Gloves required
  • Prepare reagents in fume hood
  • Avoid exposure to mists, dusts, vapor, and droplets
  • Perform in a well-ventilated area
  • Minimum observation distance is one meter

Class: Kinetics

Division: General

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