Purpose:
To demonstrate and classify the characteristics of a chemical reaction.
Objectives:
Describe the difference between a chemical and physical change.
Chemical Change- change the way it looks (you can get the original substance back)
Physical Change- create something new (cant get the original substance back)
Data table:
Chemical Composition
|
Elements involved
|
Characteristics
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Barium chloride
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Ba, Cl
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Green/light green
|
Calcium Chloride
|
Ca, Cl
|
Orange
|
Lithium Chloride
|
Li, Cl
|
Hot pink/Red
|
Potassium Chloride
|
K, Cl
|
Blue
|
Sodium Chloride
|
Na, Cl
|
Yellow/ Light orange
|
Strontium Chloride
|
Sr, Cl
|
Red
|
Aluminum foil
|
Al
|
Sparks
|
Mystery Substance (Sodium and Lithium)
|
Na, Li
|
Orange
|
Here are some videos to the colors:
http://www.youtube.com/watch?v=j3SWXAtjRBY
http://www.youtube.com/watch?v=17i79eqvN5Q
http://www.youtube.com/watch?v=j3SWXAtjRBY
http://www.youtube.com/watch?v=17i79eqvN5Q
Analysis Questions:
1.) What indicators (at least 3) determine that a chemical change (or reaction) has occurred?
Some indicators that determine that a chemical reaction has occurred are energy being absorbed or given off n a reaction, a change in color, change in odor, a liquid producing a gas or a solid, and when a new substance is created.
Some indicators that determine that a chemical reaction has occurred are energy being absorbed or given off n a reaction, a change in color, change in odor, a liquid producing a gas or a solid, and when a new substance is created.
2.) What is emitted when a chemical change takes place in the flame test?
In a Flame test, a new color is emitted.
In a Flame test, a new color is emitted.
3.) What group, from the periodic table, do these elements exist?
The elements used ion this experiment are in the Alkali metals group from the periodic table.
The elements used ion this experiment are in the Alkali metals group from the periodic table.
4.) Do any two elements give the same spectrum of color? Explain why?
Yes, there are some cases where two elements give you the same spectrum of color. This can happen because of the reaction of the electrons to heat. Many electrons react the same way, giving off the same color.
Yes, there are some cases where two elements give you the same spectrum of color. This can happen because of the reaction of the electrons to heat. Many electrons react the same way, giving off the same color.
5.) Recall what a catalyst is in a chemical reaction. What was the catalyst in these reactions?
A catalyst in a reaction is what drives the reaction. For example, in this experiment, the catalyst was heat. If there wouldn't have been any heat, there wouldn't be any reaction.
Post Lab Question:
Critical Thinking: Explain how the data gathered in this lab can be used to solve crimes or convict criminals.
In the flame test, you see the type of reaction an element has, when under the conditions of a . When there is a mixture of elements, you can tell what the components of the mixture are. To solve crimes, forensic scientists have different ways to find out what a things is made of, or what causes them to react a certain way. This process is also used to identify the make-up of chemical contamination in chemical spills, land fills and industrial sites. They do that to determine if those things are a threat to human health.
For more information, visit: http://www.myteacherpages.com/webpages/csogn/files/Lab%20Flame%20Test%201109.pdf
For more information, visit: http://www.myteacherpages.com/webpages/csogn/files/Lab%20Flame%20Test%201109.pdf
