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Teaching Guide
Light Stick Chemistrp
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  1. In step 3, why was it necessary to place the light sticks in the water-filled beakers for several minutes before performing the activity?
    (During this time the temperature of the light stick chemicals changed to reflect the temperature of the surrounding water.)
  2. In step 6, why was it necessary to include all three sticks in the same image?
    (This way you could compare the relative brightness of the sticks).
  3. In which beaker did the stick glow brightest?
    (warm water)
  4. In which beaker did the stick glow dimmest?
    (ice water)
  5. In which beaker did the glow last longest?
    (ice water)
  6. In which beaker did the glow go away the quickest?
    (warm water)
  7. Is the brightness of the glow related to the time that this effect lasts? Explain.
    (Yes. The brightest glow (warm water) lasts the shortest time. Likewise, the dimmest glow (ice water), lasts the longest.)
  8. The rate of a reaction is dependent upon several factors, including the temperature of the reaction vessel. How can this concept be applied to your observations?
    (Warm water beaker: At a higher temperature, the reaction proceeded at a faster rate. This produced a brighter glow. Since the reactants were used up quicker, the glow ended sooner. Cold water beaker: In contrast, the cooled stick contained a slower reaction. This produced a reduced glow that lasted a longer period.)


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