- In step 3, why was it necessary to place the light sticks
in the water-filled beakers for several minutes before performing
(During this time the temperature of the light stick
chemicals changed to reflect the temperature of the surrounding
- 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
- In which beaker did the stick glow brightest?
- In which beaker did the stick glow dimmest?
- In which beaker did the glow last longest?
- In which beaker did the glow go away the quickest?
- 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
- 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.)