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Blue Bottle Reaction

Materials

Procedure

  1. Just before class starts, add glucose and 4 drops methylene blue solution to the KOH solution and mix until clear.
  2. Show the class the stoppered flask containing the solution.
  3. Give the flask a few shakes. The solution will turn blue.
  4. After a few seconds, solution becomes clear.
  5. This process can be repeated several times. The bottle may have to be unstoppered to introduce O2.

Reactions

O2 (g) --> O2 (dissolved)

O2 (dissolved) + methylene blue --> methylene blue
                             (colorless)                  (blue)

glucose + OH- --> glucoside

glucoside + methylene blue --> methylene blue + OH-
                        (blue)                   (colorless)


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Last Updated: 5/23/02