SNC1D Forensic Science Name

SNC1D Forensic Science Name: Date:

Background Information: Somebody eating at a popular restaurant suddenly fell ill. A suspicious white powder was found on the victim. As chief crime scene investigator, your job is to identify the white powder that was collected on the victim. It may be the same substance as one of the five different white powders stored at the restaurant. This substance may be the cause of the illness, or it may simply be a harmless, edible cooking ingredient. You decide to compare the physical and chemical properties of the unidentified powder to the properties of the five known substances. Once the mystery powder is identified, you will be able to solve the crime!!

Purpose: To identify a powder based on its physical and chemical properties.

 DO NOT TASTE ANY SUBSTANCE. Materials:  IODINE SOLUTION AND SOME POWDERS ARE  Goggles HAZARDOUS.  Well plate  WASH YOUR HANDS AFTER THE LAB  Toothpicks  Wooden Splints  6 powders (asprin, baking powder, baking soda, icing sugar, cornstarch, unknown substance)  Test solutions in dropper bottles (water, universal indicator, vinegar, iodine solution) Procedure: 1. Put on your goggles. 2. Observe the physical properties of each powder and record your observations in the data table. 3. Using a wooden splint, add a small sample of each powder to the top row of a spot plate. 4. Add a small amount of water and mix with a toothpick. Record your observations in the data table. 5. Add a drop of universal indicator to each of the powder mixtures and mix well with the toothpick. Record your observations. 6. Using a wooden splint, add a small sample of each powder to the second row of a spot plate. 7. Add a small amount of vinegar and mix with a clean toothpick. Record your observations in the data table. 8. Using a wooden splint, add a small sample of each powder to the third row of a spot plate. 9. Add a small amount of iodine solution and mix with a clean toothpick. Record your observations in the data table. 10. Obtain a sample of mystery powder and observe the physical properties. Record your observations in the data table. 11. Using a wooden splint, add a small sample of the mystery powder to three of the wells in the fourth row of a spot plate. 12. Add a small amount of water to one of the mystery powder wells and mix well with a toothpick. Record your observations in the data table. 13. Add a small amount of universal indicator to the same well as the water/powder mixture and mix well with a toothpick. Record your observations in the data table. 14. Add a small amount of vinegar to one of the mystery powder wells and mix well with a clean toothpick. Record your observations in the data table. 15. Add a small amount of iodine solution to the last of the mystery powder wells and mix well with a clean toothpick. Record your observations in the data table. 16. Clean up your equipment. Clean up your lab station. Wash your hands.

Data and Observations: SUBSTANCE PHYSICAL PROPERTIES CHEMICAL PROPERTIES (WHAT IT LOOKS LIKE) (HOW IT REACTS)

Water Universal Vinegar Iodine Indicator Solution

Icing Sugar Cornstarch Asprin Baking Soda Baking Powder Mystery Powder

Conclusion: 1. Identify any evidence of chemical changes in each test.

2. Use the evidence from your tests to identify the mystery powder.

3. Which properties (physical or chemical) were the most useful in identifying the mystery powder?

4. What other properties could have helped to identify the mystery powder?