Iodine clock reaction. At left, a clear solution of potassium iodide, sodium thiosulfate, and starch is added to a clear solution of hydrogen peroxide

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Iodine clock reaction. At left, 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. A digital clock is started. At right, a 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.

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Size: 6994px × 2573px
Photo credit: © MARTYN F. CHILLMAID/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: -, acid, background, chemical, chemistry, clear, clock, colorless, colourless, conical, digital, education, equilibrium, flask, h2o2, hydrogen, iodide, iodine, kinetics, peroxide, potassium, reaction, school, science, sodium, solution, starch, sulfuric, sulphuric, thiosulfate, time, timer, white