The Case of the Mysterious White Powder

Abstract:
Students, it’s now time for you to prove your labworthyness, as your knowledge is critical to solving the case. You will need to record data in your notebooks. Make sure your handwriting is legible and well organized.

Background: Mr. Luigi is one of the best bakers in the land. So good in fact, that everyone is willing to pay him one hundred gold coins to buy and enjoy his delicious cakes. One day Luigi got a very special request. The Princess asked if Luigi would bake a cake for her birthday party! Luigi was happy to accept because the Princess was one of the most popular people in the land. If he baked a perfect cake, who knows what it might lead to. Day and night he worked perfecting his recipe until it was just right for the Princes s. When the day finally arrived, Luigi headed over to the castle with all of his ingredients. Just as he finished mixing the batter together, a cry came from outside. Luigi rushed out to see what all the commotion was about. After stomping and kicking some Koopa shell, he headed back to the kitchen to put the finishing touches on the cake. Luigi was so proud to deliver the cake and see the smile on the Princess’s face. Songs were sung, and pieces were passed around to all the attendants. But Luigi was horrified as he watched person after person spit out their cake! Even after tasting it himself Luigi could barely finish two bites before spitting it out. What could have gone wrong? Someone must have come into the kitchen to sabotage his cake. Luigi is a master baker, so who ever came into the kitchen must have added something that looked like it should have been part of the cake, otherwise he would have spotted it during baking. Officer Sox was called in and after investigating the crime scene and the party’s attendants he found trace evidence on several individuals. Below is what Officer Sox collected.

Sample A - Powder taken off of Bowser’s shell

Sample B - Powder found in Daisy’s make-up bag

Sample C - Powder removed from Toad’s toadstool

Sample D - Powder lifted from Donkey Kong’s bananas

Sample E - Powder from underneath Yoshi’s egg

Sample F - Powder picked up on Mario’s overalls

Directions:
All Data and information must be recorded in your lab portfolio. Start by writing a title for the lab and writing a purpose statement describing what you are trying to accomplish.

Make a data table section in your portfolio and draw a large table that can hold all the test results. There are six mystery powders and four tests on each powder. Follow the directions below for the four test:

You only need one spoonful of each powder for the lab. You may use the weigh boats to transport the powder to your desk, but then divide the spoonful into 4 equal portions for each of the test below.

1) Observe one portion of each of the different powders. In your lab portfolio, record differences in the different samples (texture, feel, how fine the powder is). You will not receive credit for saying they are all white.

2) Conduct a test with vinegar. Add a few drops of vinegar to a new portion of each mystery powder. Record if the powder fizzes, or does not fizz.

3) Conduct an iodine test, a test that indicates if starch is present. Add a few drops of Iodine tincture to a new portion of each mystery powder. Record if there is a positive or negative test. A positive test is indicated by a dark blue/black color ink. A negative test remains the same reddish/brown color.

4) Conduct a heat test. Make six small containers out of aluminum foil. Add one new portion of each powder to a new container and using the tongs, heat by moving it back and forth across the Bunsen burner for 30 to 45 seconds. Discontinue heating if burning begins. Record observations in color and if the texture changes.

Additional Assignments: These must be included in your Lab Report!!!!

1) CP and Honors: After you have constructed your data table, request that Officer Sox come and verify your data. He will then present you with a sample of Luigi’s batter from the kitchen. Conduct all four test for Luigi’s cake batter. Record the outcome from each of the test. Then, in a short paragraph, answer the question of who is responsible for sabotaging Luigi’s cake. Explain details and support your answer based on results from your earlier test.

2) CP and Honors: Using the information below you must identify the specific identity of each of the powders. Compare the statements below to your test data to match the mystery powder with its identity.

3) Honors: Additionally, your group must construct a flow chart or tree diagram that illustrates a process for identifying the unknown powders. Each of the tests must be included, and there must be different pathways that eventually lead to the identity of each of the six powders.

The following is an analysis of the different powders used in today’s lab:

1) Baking Soda does not respond to iodine, and fizzes in response to vinegar.

2) Baby Powder turns grey when heated, and does not react with iodine or vinegar.

3) Corn starch is a bright white and silky texture. It turns blue/black in Iodine, but does not fizz.

4) Baking Powder has a positive test for both vinegar and Iodine.

5) Powdered sugar has a negative test for Iodine and vinegar, but caramelizes when heated.

6) Flour is a dull, off white powder that does not fizz, but has a positive test for Iodine.