Substance Identification Lab

A Forensics Lab

Yesterday at 3 AM, at Mike's Awesome Bakery in Francestown, NH the baker arrived to find his assistant baker dead: lying in a pool of blood.  The victim's body was covered in a white powder.  

In an attempt to find the source of the white powder, investigators collect multiple samples from the bakery (baking soda, flour, baking powder, powdered milk, cornstarch).
Investigators are in the process of interviewing employees of the bakery to narrow their field of suspects.  They are also gathering clothing samples from employees to find a match for the white powder.




Today in our science class we were assigned a lab. Our goal to find out an unknown substance by comparing it to other substances. The four known substances were Baking Soda, Baking Powder, Flour, and Cornstarch. We observed the substances' chemical reactions to different liquids. These different liquids were Water, Vinegar, Iodine, and Universal Indicator. Next, we compared the unknown substance to the known substances. In doing so, we were able to come to a conclusion on what the unknown substance was....

Procedure

Step 1: Gather necessary materials and equipment.

• Cups
• Baking Soda
• Baking Powder
• Flour
• Cornstarch
• Unknown Substance
• Iodine
• Water
• Vinegar
• Universal Indicator
• A Clean Surface
• Pencil
• Safety Glasses
• Paper
• Pipette

Step 2: One at a time, put the substances (flour, baking soda, baking powder, and cornstarch) on the chart provided in the correct space.

Step 3: Take each chemical and put two to three drops of each chemical on each substance.

Step 4: Record the results on how each substance reacted to the chemical.

Step 5: Repeat steps 2-4 on all of the substances.

Step 6: Compare all the reactions and determine which  substance reacted the most alike the unknown substance.

Conclusion: After completing the procedure we came to the conclusion that our unknown substance was baking powder. We were able to determine this pretty easily because of the noticeable similarities with the way the chemicals reacted to the substances.