The iodine clock reaction (also known as the Harcourt-Esson reaction or the Harcourt-Essen reaction) is a classical chemical clock demonstration experiment to display chemical kinetics in action; it was discovered by Hans Heinrich Landolt in 1886. Two colorless solutions are mixed and at first there is no visible reaction. After a short time delay, the liquid suddenly turns to a shade of dark blue. The iodine clock reaction exists in several variations. In some variations, the solution will repeatedly cycle from colorless to blue and back to colorless, until the reagents are depleted.
Read more about Iodine Clock Reaction: Hydrogen Peroxide Variation, Iodate Variation, Persulfate Variation, Chlorate Variation
Famous quotes containing the words iodine, clock and/or reaction:
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—Administration in the State of Sout, U.S. public relief program (1935-1943)
“What says the Clock in the Great Clock Tower?
And all alone comes riding there
The King that could make his people stare,
Because he had feathers instead of hair.
A slow low note and an iron bell.”
—William Butler Yeats (1865–1939)
“More and more, when faced with the world of men, the only reaction is one of individualism. Man alone is an end unto himself. Everything one tries to do for the common good ends in failure.”
—Albert Camus (1913–1960)