What is the white powder?

White powder test?

A forensic scientist may discover powder at a crime scene. In order to determine if it is illegal or not the crime lab will identify the substance using chemistry. Take on the role of a forensic chemist to identify unknown substances.

Become a Forensic Chemist by following these procedures and filling in the Powder Analysis Chart with your results. 

Complete the appearance, texture, and smell activities before opening the vinegar and iodine bottles.

Record your findings in the Powder Analysis Chart below.

Aim: To determine how different powders feel, look and react to other substances.

Hypothesis: It will dissolve

Equipment: 

 Baking Soda 

 

Cornflour 

 

Sugar 

 

Salt 

 

Iodine 

 

Vinegar 

 

Magnifying glass 

 

Eye drop 

 

Black card 

 

Tea spoon / stick

Method: 

1. Place one-fourth teaspoon (1 ml) of the four white powders on a sheet of black construction paper. Label the powders with your pen.
2. Study the powders with the magnifying glass. Examine what each powder looks like. How would you describe the powder's shape. Does it have large or small grains? Your observations should be written in the appearance column of the chart.
3. Examine the powders further by rubbing each powder between your fingers. Describe how each powder feels in the Texture column of the chart.
4. Determine if there is a smell to any of the powders. Record your findings in the Smell column of the chart.
5. Take the eyedropper and place a drop of water on each individual powder. Examine what happens? Do the powders dissolve? Is there a reaction? Write your observations in the Reaction to Water column.
6. Place one-half teaspoon (2ml) of each powder in a separate jar. Add 2 drops of iodine to each jar using the eyedropper. Record what happens in the Reaction to Iodine column. Iodine should be handled with care.

Findings:  

Powder Analysis Chart

                                                                                                  

Substance    Appearance   Texture    Smell     Water     Vinegar     Iodine

Cornflour = B           - small           - smooth      - No Smell - Dissolves           - Doesn't dissolve

Sugar = D                - large            - Course       - Dead ant - Dissolves           - Doesn't dissolve

Salt = C                   - medium        - Fine           - No Smell - Dissolves           - Doesn't dissolve

Baking soda = A     -medium          - Fine          - No smell - Dissolves           - Dissolve

Comparing test results of substances that are known help Forensic Scientists identify unknown substances.

Summary: