Shakira Cruz
Chemistry Class
H23
- Purpose: To demonstrate and classify the characteristics of a chemical reaction.
- Objective: Describe the difference between a physical and chemical change.
Data Table:
Chemical Compound
|
Elements Involved
|
Characteristics
|
Barium Chloride
|
Barium
|
Gives off a green
color
|
Calcium Chloride
|
Calcium
|
Gives off a orange
color
|
Lithium Chloride
|
Lithium
|
Gives off a red color
|
Potassium Chloride
|
Potassium
|
Gives off a violet
purple color
|
Sodium Chloride
|
Sodium
|
Gives off a bright
orange color
|
Strontium Chloride
|
Strontium
|
Gives off a orange
red color
|
Aluminum Foil
|
Aluminum
|
Sparkles (resembles a
firework)
|
Unknown
|
Lithium &
Potassium
|
Red & Violet
Purple Color
|
Characteristics
Demonstration of The Flame Test
- Analysis Questions:
What indicators (at least 3) determine that a chemical change (or reaction) has occurred? The three indicators that determine that a chemical change (or reaction) has occurred are the gas and vapor that came from the blaze, and the energy that was consume or given off in the reaction.
What is emitted when a chemical change takes place in the flame test? As the chemical change takes place in a flame test the unknown combination releases vapor and bubbles.
What group, from the periodic table, do these elements exist? The group that the elements exist in the periodic table are in the metals: Alkaline metals and the Alkali metals, which are the group 1 & 2.
Do any two elements give the same spectrum of color? Explain why. There are two elements that give the same spectrum of color and they are the calcium and sodium, which both had a shade of orange. The chemical compound "Strontium" had a variety of colors from other combinations. For example, pink and orange which is found in calcium. Within all the compounds that was tested in class, the unknown compound had the most colors.
Recall what a catalyst is in a chemical reaction. What was the catalyst in these reactions? A catalyst is a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change. So the catalyst in the flames reaction is when the compound reacted to the gas created colors.
Critical Thinking: How the data gathered in this lab can be used to solve crimes or convict criminals?
The data gathered in this lab can be used to solve crimes or convict criminals. There are highly specialized teams of Forensic Scientist that test either, fingerprinting, human remains, firearms, explosives and so on. As stated by the Forensic Chemistry site, "Forensic investigators consult a wide range of experts who analyze evidence collected at crime scenes and brought to the crime laboratory for examination" ("Forensic Chemistry", par. 1). The physical evidence that is collected in a crime scene is sealed in special containers to avoid any contamination and is then sent to the forensic laboratory. According to the article, the strength of a prosecution rests on the ability of law enforcement personnel to connect the accused with the victim by matching physical evidence from the crime scene or victim with trace evidence found on or about the person accused of the crime.
At the laboratory, the evidence is examined by personnel trained in one of several fields: Forensic serologists examine body fluids, forensic pathologists examine human remains, firearms technicians classify and test firearms and explosives, and forensic chemists determine the composition and identity of materials. The forensic scientist is always a key factor in determining the criminal in a crime scene.
Bibliography:
http://www.chemistryexplained.com/Fe-Ge/Forensic-Chemistry.html
The Step by Step Flame Test Video
Critical Thinking: How the data gathered in this lab can be used to solve crimes or convict criminals?
The data gathered in this lab can be used to solve crimes or convict criminals. There are highly specialized teams of Forensic Scientist that test either, fingerprinting, human remains, firearms, explosives and so on. As stated by the Forensic Chemistry site, "Forensic investigators consult a wide range of experts who analyze evidence collected at crime scenes and brought to the crime laboratory for examination" ("Forensic Chemistry", par. 1). The physical evidence that is collected in a crime scene is sealed in special containers to avoid any contamination and is then sent to the forensic laboratory. According to the article, the strength of a prosecution rests on the ability of law enforcement personnel to connect the accused with the victim by matching physical evidence from the crime scene or victim with trace evidence found on or about the person accused of the crime.
At the laboratory, the evidence is examined by personnel trained in one of several fields: Forensic serologists examine body fluids, forensic pathologists examine human remains, firearms technicians classify and test firearms and explosives, and forensic chemists determine the composition and identity of materials. The forensic scientist is always a key factor in determining the criminal in a crime scene.
Bibliography:
http://www.chemistryexplained.com/Fe-Ge/Forensic-Chemistry.html
