Evanelly Cruz                          H-18                   November 4, 2013
 
                                    Flame Test Experiment

Purpose: To demonstrate and classify the characteristics of a chemical reaction.

Objective: Describe the difference between a physical and chemical change.
Example: 

Data Table:

Chemical Compounds :	Elements involved:	Characteristics:
Barium Chloride	BaCl	Green
Calcium Chloride	CaCl	Orange
Lithium Chloride	LiCl	Pink
Potassium Chloride	KCl	Blue
Sodium Chloride	NaCl	Orange/yellowish
Strontium Chloride	SrCl	Red
Aluminum foil???	Al	Sparks up.
Mystery Substance	LiBa	Green/pink

Analysis Questions:

1.) What indicators (at least 3) determine that a chemical change (or reaction) has occurred?

 * Three indicators that help determine that a chemical change or reaction has occurred is the change in color, the change in order and energy is absorbed or given off in a reaction.

2.) What is emitted when a chemical change takes place in the flame test?

 * In this flame test, the change in color is emitted when there is a chemical change.

3.) What group, from the periodic table, do these elements exist?

 *Some elements exist on the Metal, Alkali Earth Metals and Alkali Metal group. Barium, Calcium and Strontium are on the Alkali Earth Metal groups. Lithium, Potassium and Sodium and on the Alkali Metal group and Aluminum is on the Metal group on the Periodic table.

4.) Do any two elements give the same spectrum of color? Explain why?

 *Calcium and Sodium are both an orange color. When the Calcium Chloride was put into the flame it turned orange and when the Sodium Chloride was put into the flame it was an orange/yellowish color.

5.) Recall what a catalyst is in a chemical reaction.  What was the catalyst in these reactions?* A catalyst in a chemical reaction is used to separate the different compounds into elements. You can use heat to separate sugar and electricity to separate water into its elements. In this reaction, the catalyst separates and show us different colors.

Videos:

http://youtu.be/jJvS4uc4TbU (2:01)
http://youtu.be/EXiXwdKpw_U (0:34)
http://youtu.be/ZcRfitm6caw (2:47) FORENSIC

Post lab question:

Critical Thinking: Flame test in crime scenes are used to identify elements in a substance. If you have a substance on your clothes the forensic scientist would be able figure out if it was you who committed the crime. For example, If a suspect used a weapon like a gun they'll be able to find the substance in the gun powder. We would be able to find out who did the crime.
          Some of the elements are in the Alkali Metal group which means some weapons may contain these elements in them. I learned the Lithium Deuteride is used in thermonuclear weapons. Sodium is used as luster in metals. You can find different elements in or on a weapon. That can help you get closer to finding the suspects and solve the crime.   
  

Source: http://21001csi.blogspot.com/2011/08/trace-elements-flame-test.html
http://tough-call.co.uk/forensics/flame-test.html
http://education.jlab.org/itselemental/ele003.html