H-18
10-30-13
Flame Test Experiment
Purpose: To demonstrate and classify the characteristics of a chemical reaction
Objective: Describe the difference between a physical and chemical change
Date Table
Chemical compounds Element Characteristics
Barium Chloride
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Ba+ Cl
|
Green color
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Calcium Chloride
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Ca+ Cl
|
Orange color
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Lithium Chloride
|
Li+ Cl
|
Brick red color
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Potassium Chloride
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K+ Cl
|
Lilac color
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Sodium Chloride
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Na+ Cl
|
Yellow color
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Strontium Chloride
|
Sr+ Cl
|
crimson color
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Aluminum Foil
|
Al
|
Put around rushed metal to produce a spark. Used in fireworks for added sparkle
|
Mystery substance
|
Li+ Ba
|
Red and Green
|
Analytical Questions
1.) What characteristics determine that a chemical change (or reaction) has occurred?
The change of odor, color, or if a liquid produces a gas or solid, can be indicators of a chemical reaction.
2.) What is emitted when a chemical change takes place in the flame test?
A change of color is emitted in the flame test.
3.) What group, from the periodic table, do these elements exist?
Strontium, Barium, and Calcium are alkaline earth metals. Sodium, Potassium, and Lithium are alkali metals.
4.) Do any two elements give the same spectrum of color? Explain.
Lithium and Strontium share the same reddish tint because they have lower energy levels.
5.) Recall what a catalyst is in a chemical reaction. What was the catalyst in these reactions?
A catalyst in a chemical reaction is what starts or speeds up the reaction. The catalyst in this test is heat (the flame).
Picture explaining flame colors
The colors to the left are the ones with the highest frequency (highest) levels.
Video of flame test
Post Lab Question
Data from a flame test can be used to determine what was used to kill a victim. Since you know what colors an element emitted when subject to a flame, a flame test can be used to determine what substance was used. If there is a crime scene and the criminal left behind a "white substance" a flame test can be used to identify what the substance was. The colors that the substance eludes can lead way to what elements make the substance up. Once the elements are found chemists can find out what substance is made up of those elements, and determine cause of death.