MARTYN F. CHILLMAID / SCIENCE PHOTO LIBRARY MARTYN F. CHILLMAID / SCIENCE PHOTO LIBRARY
Iodine clock reaction. This is the end of the experiment. A clear solution of potassium iodide, sodium thiosulfate, and starch is added to a clear solution of hydrogen peroxide with sulfuric acid in the conical flask. Chemical equilibrium has been reached when the solution turns a dark blue/black. The digital timer is stopped and the reaction time is read off.
Model release not required. Property release not required.