Blue+Bottle+Experiment

=__The "Blue" Bottle Demo__=
 * Materials** (for 1 demonstration)


 * gloves
 * goggles
 * lab coat
 * 250 mL erlinmeyer flask with rubber stopper (or bottle of equivalent size)
 * 100 mL of a 5% NaOH solution
 * 5 grams of glucose
 * 1-2 mL of a 0.1% solution of indigo carmine in water
 * plastic pipet or eye dropper


 * Procedure**
 * 1) Pour sodium hydroxide solution into flask.
 * 2) Add 5 grams of glucose and allow to dissolve.
 * 3) Add the deep blue indigo carmine solution. Solution should immediately turn yellow-green.
 * 4) Carefully stopper the flask.
 * 5) Shake to mix solution and ensure yellow-green color.
 * 6) Set the flask aside (this is a good time to explain the chemistry of the demonstration). The liquid will gradually become red as glucose is oxidized by the dissolved oxygen. A thin yellow boundary can be expected to remain at the solution-air interface, since oxygen remains available via diffusion.
 * 7) The yellow-green color of the solution can be restored by swirling or shaking the contents of the flask.
 * 8) The reaction can be repeated many times.


 * Notes**


 * Be careful with the hydroxide solution, it is corrosive.
 * The reaction can be performed with methylene blue to make a solution that alternates between colorless and blue. Indigo carmine is more colorful and almost non-toxic.
 * The warmer the solution is the more green (rather than yellow) it will be after shaking.
 * The reaction neutralizes over time and can be safely poured down the sink after the demo.

Here is a video of the traditional blue bottle experiment using methylene blue:
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