Repurposed Lesson White Powder Lab- using Kidblog to share, interact and collaborate with peers

White Powder Lab: Using Properties and Chemical Change to Identify and Unknown Prepared by: Jamie Vandenburgh Subject area: Science Technology used: Kidblog-using iPads Length of lesson: 50-60minutes Suggested grade level: 7 th grade Science

Materials: (for each group) Handout: White Powder Observation Record form Handout : White Powder Reactivity Chart (laminated) Handout: White Powder Student Journal pages (2) 5 Soufflé cups, 2oz. 5 craft sticks 4 squeeze bottles Cornstarch Baking Powder Baking Soda Cream of Tartar Water Vinegar Iodine Universal Indicator Measuring spoon Safety Goggles *Not all materials are shown in picture

Before During a class discussion ask “What tests could you conduct with the white powder to compare their properties?” Encourage students to think about some of the different procedures and materials they used in the previous activities. Ask how they might measure the pH, and reactivity of each substance. Show the students their materials and allow them to come up with ideas and procedures.

Handouts White Powder Reactivity Chart- This chart is laminated so that students can conduct the experiment directly on the chart. White Powder Lab Observation Record Form- Student’s will make observations about each substances physical properties and record reactivity of substances here.

Procedures Part 1: 1. Record your observations of each powder on the White Powder Observation Form. 2. Use the craft sticks to place 4 equal samples of baking soda on the testing chart. (I have completed the first 2 columns) 3. Add 3-4 drops of water to the first pile of baking soda. Record your observations on the White Powder Observation Record Form. (To showcase the reactivity of the substances I have skipped to Iodine)

Procedures 4. Repeat step #3 using the remaining testing solutions. (Vinegar, iodine, universal indicator) 5. Repeat steps 1-4 using the remaining test powders. (Baking Powder, Cream of Tartar, and cornstarch) Pictured: All steps using Iodine and the 4 white powders

Procedures 6. Retrieve an unknown sample from your instructor. Repeat steps 1-6 on the un-known sample Pictured: We can deduce from the reactivity of the substance with the Iodine that it is either Baking Powder or Cornstarch. Using the other tests student’s will be able to identify the unknown.

After Write a blog post for your investigation using a claim (Identify your unknown), evidence, and reasoning. Answer the Teacher blog post and comment on a classmate’s response. Teacher Blog post: Ask students how testing and comparing properties and reactivity of substances is useful in identifying unknown substances. Reflect on the identification of unknowns as one of the activities of Chemistry. Discuss the variables that were controlled in the tests. Discuss how a substance reacts chemically in characteristic ways and that these characteristics can be used to identify an unknown substance.