Purpose: To demonstrate and classify the characteristics of a chemical reaction.
Objective: Describe the difference between a physical and chemical change.
Data Table:
Analysis Questions:
1.) What indicators (at least 3) determine that a chemical change (or reaction) has occurred? Three indicators that determine that a chemical change has occurred are when energy is absorbed or given off in a reaction like the heat from burning gas on a stove, change in color, and last but not least change in odor. An example of a chemical change would be burning a log of wood.
2.) What is emitted when a chemical change takes place in the flame test? When a chemical change takes place in a flame test light is emitted. When the atoms are placed in heat the electrons energy level raises higher but returns to their lowest energy level when the heat from the flame is removed. This allows them to produce wave lengths and eventually lead to the color that is emitted when the atoms are placed in heat.
3.) What group, from the periodic table, do these elements exist? The elements involved in this experiment make up the boron group like Aluminum or alkali earth metals like Barium, Calcium, and Strontium. They are also apart of alkali metals like Sodium, Potassium, and Lithium.
4.) Do any two elements give the same spectrum of color? Explain why? Some of the elements give off a similar color of flame but not exactly the same color like for example Lithium chloride gives of hot pink, yellow, and blue while sodium chloride just gives off yellow and this can just be caused by the compound being apart of the same group on a periodic table.
5.) Recall what a catalyst is in a chemical reaction. What was the catalyst in these reactions? Catalyst are substances that help "jump start" or speed up a chemical reaction. The catalyst in these reaction was the heat which caused electrons energy levels to fluctuate giving off colors in the end.
video*http://www.youtube.com/watch?v=A9o83pisI_0
Post-Lab Questions:
Critical Thinking: In your blog, explain how the data gathered in this lab can be used to solve crimes or convict criminals. Research the topic and use what you discovered in class to write 1-2 paragraphs on answering question. *Be sure to cite your source.
Flame testing is a very useful experiment conducted when trying to solve a crime or convict a criminal. Forensic scientist use flame testing in order to figure out if a victim has a poisonous element or compound found in their blood stream. Poisonous elements like lead would give off a certain color if that persons blood was tested with a flame test letting them know that the victim was indeed poisoned. If the victim was poisoned with lead for example the flame test would show a pale green color which is the color that lead gives off . Basically what a flame test does is allow the scientist or chemist know what kind of substance they are dealing with and whether or not it can be useful when trying to figure out a reason behind a persons death.
Works Cited:
- http://www.webexhibits.org/causesofcolor/3BA.htm
- http://webmineral.com/help/FlameTest.shtml#.UnxL-Bh3SD8
- http://chemistry.about.com/b/2013/06/04/toxic-elements.htm
- http://www.slideshare.net/petrovus/flame-test-part-2
1.) What indicators (at least 3) determine that a chemical change (or reaction) has occurred? Three indicators that determine that a chemical change has occurred are when energy is absorbed or given off in a reaction like the heat from burning gas on a stove, change in color, and last but not least change in odor. An example of a chemical change would be burning a log of wood.
2.) What is emitted when a chemical change takes place in the flame test? When a chemical change takes place in a flame test light is emitted. When the atoms are placed in heat the electrons energy level raises higher but returns to their lowest energy level when the heat from the flame is removed. This allows them to produce wave lengths and eventually lead to the color that is emitted when the atoms are placed in heat.
3.) What group, from the periodic table, do these elements exist? The elements involved in this experiment make up the boron group like Aluminum or alkali earth metals like Barium, Calcium, and Strontium. They are also apart of alkali metals like Sodium, Potassium, and Lithium.
4.) Do any two elements give the same spectrum of color? Explain why? Some of the elements give off a similar color of flame but not exactly the same color like for example Lithium chloride gives of hot pink, yellow, and blue while sodium chloride just gives off yellow and this can just be caused by the compound being apart of the same group on a periodic table.
5.) Recall what a catalyst is in a chemical reaction. What was the catalyst in these reactions? Catalyst are substances that help "jump start" or speed up a chemical reaction. The catalyst in these reaction was the heat which caused electrons energy levels to fluctuate giving off colors in the end.
video*http://www.youtube.com/watch?v=A9o83pisI_0
Post-Lab Questions:
Critical Thinking: In your blog, explain how the data gathered in this lab can be used to solve crimes or convict criminals. Research the topic and use what you discovered in class to write 1-2 paragraphs on answering question. *Be sure to cite your source.
Flame testing is a very useful experiment conducted when trying to solve a crime or convict a criminal. Forensic scientist use flame testing in order to figure out if a victim has a poisonous element or compound found in their blood stream. Poisonous elements like lead would give off a certain color if that persons blood was tested with a flame test letting them know that the victim was indeed poisoned. If the victim was poisoned with lead for example the flame test would show a pale green color which is the color that lead gives off . Basically what a flame test does is allow the scientist or chemist know what kind of substance they are dealing with and whether or not it can be useful when trying to figure out a reason behind a persons death.
Works Cited:
- http://www.webexhibits.org/causesofcolor/3BA.htm
- http://webmineral.com/help/FlameTest.shtml#.UnxL-Bh3SD8
- http://chemistry.about.com/b/2013/06/04/toxic-elements.htm
- http://www.slideshare.net/petrovus/flame-test-part-2
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