La! Crime Investigation Unit:

Where Did Tony Drown? Was it an Accident?

Test #3:

You will use chemical tests to identify the white powder found under Tony’s nails.  Use the flow chart below to help identify the compound.

1. Place one spoonful of each known powder in a section of you well-plate. Use the table below to help you

Example of well-plate setup 

  2.   Examine the physical characteristics (color, shape, size, texture, etc.) of each KNOWN powder.  Record your observations in Data Table 3 Analysis of Unknown White Powder. 

  3.    Carefully pour a small amount of acetic acid over each place a small amount of acetic acid (less then 5 mL) over each KNOWN sample.  Record your observation in Data Table 3 Analysis of Unknown      White Powder.

4.      Add one spoonful of the powder collected from the victim’s nails to a clean well in your well plate. 

5.      Carefully pour a small amount of acetic acid over each place a small amount of acetic acid (less then 5 mL) over the UNKNOWN sample.  Record your observation in Data Table 3 Analysis of Unknown White Powder.

6.     Write your conclusions on the Evidence Report Sheet. 

7.      Return to Test #2 then CLEAN UP