Dark red iron[III] solution is rapidly reduced to colorless iron[II] by addition of tin[II] chloride solution, with the rate depending on concentration and temperature.
Four medium footed cylinders are prepared with 100 ml of ferric chloride solution 0.01M with potassium thiocyanate solution added to make the dark red complex. One of the solutions should be hot, so just the iron and thiocyanate solutions in that cylinder, with a 150ml beaker for the demonstrator to fill with hot water from the water cooler, right before the demonstration.
The cylinders are on the bench top in...
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