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F A C T S 1 0

Analyzing and

Identifying White Solids


When a crime has been committed, it is the responsibility of the police, FBI, ATF, and/or sheriff to collect evidence in order to solve the crime. The evidence must be collected and analyzed properly to hold up in a court of law. In this lab, you must collect data and draw conclusions from that data. A forensics scientist can use hunches and intuition

in trying to solve a crime; however, when it comes to going to court, only actual facts should be presented. An expert witness may make inferences but he or she is subject to questioning by the defense.


Observation : a statement of fact based on what you see, hear, taste, touch, or smell. A good investigator takes careful notes of everything at the scene. Sketches and photographs are important parts of every investigation and are completed prior to touching or collecting any evidence.


Types of Observations

·         Physical properties of a substance are those characteristics that can be observed, such as color, odor, density, melting point, boiling point, hardness, conductivity, or taste.

·         Chemical properties of a substance are those characteristics that describe how the substance reacts with other chemicals.



Conclusion : a statement of fact based on the results of experimental testing. For example, if you have a white powder and add iodine solution to the powder and it turns black, you can conclude that the white powder contains starch.


Inference: a judgment or opinion based on observations and/or conclusions from testing. It is a fact that some illegal drugs are mixed with flour. If a white powder tests positive for starch , one could infer that the powder is an illegal drug mixed with flour. However, this inference would not stand up in court. A good investigator might infer that the powder was an illegal drug but should order additional testing to confirm the actual composition of the powder.



·         Make observations

·         Make inference

·         Draw conclusions

·         Solve for an unknown

·         Identify common substances which are over-the-counter drugs or compounds often used in the cutting or making of illegal drugs


The FBI Crime Lab works very closely with the pharmaceutical companies to produce tests for all new drugs as they are developed. Tests are developed to identify very small samples of a drug and files are kept to serve as reference for forensics investigations to use.

Drug identification is very important. If you arrive on the scene and find an unconscious victim who has ingested some drug, you need to identify the substance as quickly as possible. Some over - t h e –counter drugs may cause poisoning and/or death especially in children.


Background Information

In this activity you will test for common over-the-counter drugs as well as common substances which are found in illegal drugs.


Aspirin, Acetyl salicylic acid: a small sample or a solution of aspirin can be identified by adding a solution of ferric nitrate. The solution will turn brownish purple if aspirin is present. In addition to the acetyl salicylic acid (active ingredient) aspirin tablets also contains starch, silicon dioxide, and preservatives. A solution of aspirin should be acidic.

Bufferin™ (buffered aspirin ) : you should get the same results with this sample as you did for regular aspirin. In addition you may get a fizzing produced when you add HCl. This is because some aspirins are buffered by a carbonate.

Baking Soda, Sodium Hydrogen Carbonate: a sample or a solution of baking soda can be identified by adding a solution of HCl acid. When the acid is added the solution will fizz. Baking soda is used in the making of crack cocaine. A solution of baking soda should be basic.

Tylenol ™ : acetaminophen, a pain killer similar to aspirin but will not test positive for salicylic acid.

Flour: a carbohydrate of high molecular weight composed of numerous glucose units.

Sugar: s u c rose is common table sugar and is made of a glucose and a fructose unit.



1 . Add a small sample of each white powder in 4 of the wells of each column as labeled

     in the Data Table.

2. Add 5 drops of water to each sample in the first well.  Stir each mixture with a clean

    toothpick.  In the Data Table, write if the white powder is soluble (s), slightly soluble

    (ss) or insoluble (ins) in water.

3. Add 1 drop of universal indicator to each of the wells containing your sample and

    water. In the Data Table, write the color the solution turns.

4. Add 5 drops of methanol to each of the six sample in the second well. In the Data

    Table, write if the white powder is soluble (s), sightly soluble (ss) or insoluble (ins) in


5. Add 5 drops of Fe(NO3)3 solution to each of the six samples in the third well. If a

    chemical reactions occurs, you should see a brownish-purple product produced. In the

    Data Table put a “P” in the well where you see this reaction occur.

6. Add 5 drops of iodine solution to each of the six samples in the last well. If starch is

    present, the solution will turn black. Write a “B” in the Data Table if the solution turns


7. Obtain an unknown sample from the evidence box. The sample is one of the six sub-

    stances you have just tested. Identify the sample.

O b s e r v a t i o n s


Data Table


White Powders




Benzoic Acid



Sodium chloride

Water +

Universal indicator




































Record your observations in the table below.

1. Describe what happened when you added water to the sample.

a. aspirin + water ________________________________________________________________


b. sugar+ water  ________________________________________________________________


c. Bufferin+ water ________________________________________________________________


d. flour + water _______________________________________________________________


e. Tylenol+ water ________________________________________________________________


f. baking soda + water ____________________________________________________________


g. Unknown sample # _________________________________________________________