| Demonstration Experiment on Video Objective: Mechanism of an Oscillating Reaction Peter Keusch |
German version
Hazards and safety precautions:
| Safety goggles and protective gloves must be worn. The experiment should be performed in a well ventilated room. Experimental procedure: The following solutions are prepared in advance: Solution A: 410 mL of 30% hydrogenperoxide are diluted to 1.0 liter with distilled water in a 1500 mL beaker. Solution B: 43 g of potassium iodate are dissolved in about 800 mL of dist. water + 4.3 ml of conc. sulfuric acid in a 1500 mL beaker. The mixture is made up to 1000 mL with dist. water Solution C: 16 g of malonic acid and 3.4 g of manganese (II) sulfate monohydrate are dissolved in about 500 mL of dist. water in a 1500 mL beaker. 3 g of soluble starch are dissolved in 100 mL of boiling dist. water in a 150 mL beaker. The starch solution is poured into the solution of malonic acid and manganese sulfate. The mixture is diluted with dist. water to 1000 mL. 250 mL of each the solutions A and B are poured into a crystallizing dish. The mixture is stirred vigorously with a magnetic stirrer. Result: The initially colorless solution becomes amber almost immediately. Then it suddenly turns blue-black. The blue-black fades to colorless. Thus the color of the solution oscillates between clear, brownish and deep blue. 
 Video clip (Download RealPlayer .rm file)
Discussion: Briggs-Rauscher Oscillating Color Change Reaction Reference: Demonstration Experiment on Video Belousov-Zhabotinsky-Reaction
Index of Lecture Experiments 
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