Name: ______Date: ______Block: _____ 1+2+3=Black!

Purpose: To make macroscopic observations of chemical reactions and use them to solve problems Secondary: What effect do sodium hypochlorite, hydrogen peroxide, and copper sulfate have on starch when mixed with potassium iodide? Can they be used to identify starch? Hypothesis: ______Materials:

 Paper  CuSO4 (copper sulfate)  6 Pipettes (label 5/1 for stirring)  KI (potassium iodide)  Reaction surface  Starch  NaClO (sodium hypochlorite-bleach)  Cereal

 H2O2 (hydrogen peroxide)

Procedure: 1. DO NOT PLACE ANY SUBSTANCES IN ROW 5 UNTIL YOUR TEACHER INSTRUCTS YOU. 2. Use the grid below to record your data as you complete the experiment. 3. Place a reaction surface on a sheet of white paper. This will enable you to view the procedure more clearly. 4. Use the column and row labels to determine which materials belong in each square. 5. Depending on the material, add one drop, one piece, or a few grains of each chemical/substance into the reaction surface grid. 6. Begin by adding starch to row 2 in your reaction surface grid. Next add paper to row 3, and then cereal to row 4. 7. Add 1-2 drops of KI in each grid in row 1, then in row 2, etc. 8. Finally you will add the chemicals listed in each column to the reaction surface in their appropriate places. 9. Stir each mixture by forcing air from an empty pipette as directed by your teacher. 10. Watch, observe, and record your results on the grid below. Name: ______Date: ______Block: _____

Analyze: Using your experimental data, record the answers to the following questions below your data table. Write in complete sentences. 1. What color is a mixture of sodium hypochlorite (NaClO) and potassium iodide (KI)? ______2. What happens when you mix NaClO, KI, and starch? ______3. What do NaClO, H2O2, and CuSO4 have in common? ______4. What substance is found in both paper and cereal? How do you know? ______Name: ______Date: ______Block: _____ 5. What occurred when hydrogen peroxide was added to the iodized salt and starch mixture? Why did this occur? What does this indicate? ______6. What occurred when copper sulfate was added to the iodized salt and starch mixture? Why did this occur? What does this indicate? ______7. What is the control group? Explain. ______8. What variables were held constant? ______9. Was your hypothesis supported or unsupported? Explain. ______10. What can you conclude from this experiment? ______