Do Now Tape in “Vocabulary for Quiz 11” onto the next open page of your comp. book.

Glow Stick Chemistry

1.Turn to the next open page of your composition book. 2.Title the page “Glow Stick Chemistry Lab” 3.Add the title to your table of contents 4.Write this underneath the title: Question: How does the surrounding temperature of a glow stick affect the intensity of the glow? Independent Variable: ______________ Dependent Variable:_________________ Controls:__________________________

Ask the Question How does the surrounding temperature of a glow stick affect the intensity of the glow?

Glow stickVariables: What is the Independent Variable for this experiment? What is the Dependent Variable for this experiment? What are the constants? IV: The surrounding temperature of the glow stick. DV: How bright the glow stick is. Constants: Beaker, thermometer, glow stick, and amount of time.

Background Research A glow stick is made up of a plastic tube with a glass vial in it. When you bend the plastic, you break the glass vial, allowing the chemicals to mix!

Background Research A compound called Hydrogen Peroxide is inside the glass vial. Two chemicals are outside the vial: Phenyl Oxalate Ester and Fluorescent Dye Solution.

Background Research When the compounds mix, a chemical reaction occurs. This releases energy and causes the fluorescent dye to glow (same as a firefly). The faster the reaction occurs, the brighter the glowstick. When the reaction is over, the glowstick stops glowing! Temperature affects the reaction. Today we will find out how temperature affects how bright a glowstick will glow.

Hypothesis Write down your hypothesis underneath the variables in your comp. book. Remember to use an “If then “ format. For example: If the outside temperature is warm, then the glowstick will be _______. (brighter? dimmer?)

Data Table Create a data table under your hypothesis in your comp. book. BeakerTemp. ( o C)Brightness (3 = brightest, 2 = second brightest, 1 = dimmest) Control (air) Hot (hot H 2 O) Cold (ice) Group: ____

Conduct the Experiment Fill beaker with 1 cup of : (ice OR hot water OR air) on the table When directed by your teacher, break the glow stick and place it in the beaker at your desk. Measure the temperature in your data chart (for your experimental group) Once the glow stick is in the beaker, do not touch it!

Taking Temperature Readings 1.Carefully lower the bulb end of the thermometer into the beaker. 2.Hold the thermometer so its bulb is near the center of the beaker. 3.Record the temperature into your data table.

Compare Variables When directed to, send your data manager to compare your glow stick with two other temperature groups in your class and record results in your data table. Make sure you get their temperature data too! If your glow stick is the brightest, write down “3”, if it is the 2 nd brightest, write “2”, and if it is the dimmest, write “1”.

Analyzing Data and Graphing When asked to, enter your data in the excel chart at the front of the room. Choose “3” for the brightest, “2” for the 2 nd brightest, and “1” for the dimmest.

Drawing Conclusions Use complete sentences to Answer conclusions in your comp. book. CONCLUSION: 1.Was your hypothesis supported or rejected? 2.Explain your answer to question #1 using data. 3.How does the surrounding temperature of a glow stick affect the intensity of the glow? Use the data to support your results. 4.What are some human errors that could have affected your data? EXPLANATION: 1.How did the research support your results? FURTHER QUESTIONS: 1.What are some further questions?