Objective: Describe the difference between a physical and chemical change.
Data Table:
Chemical Compounds:
|
Elements Involved:
|
Characteristics:
|
Barium Chloride
| Ba | green |
Calcium Chloride
| Ca | red |
Lithium Chloride
| Li | pink |
Potassium Chloride
| K | violet/purple |
Sodium Chloride
| Na | orange |
Strontium Chloride
| Sr | hot pink/red |
Unknown???
| SrBa | pink/yellow |
Analysis Questions:
1.) What indicators (at least 3) determine that a chemical change (or reaction) has occurred?
A change of color,a change of odor, and energy is absorbed or given off in reaction.
2.) What is emitted when a chemical change takes place in the flame test?
Different color came off.
3.) What group, from the periodic table, do these elements exist?
Alkali metals, Alkaline earth metals, and Other nonmetals
Alkali metals, Alkaline earth metals, and Other nonmetals
4.) Do any two elements give the same spectrum of color? Explain why?
Strontium chloride and Lithium chloride
5.) Recall what a catalyst is in a chemical reaction. What was the catalyst in these reactions?
Heat
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.
http://chemistry.about.com/b/2013/03/19/crime-scene-chemistry-test-for-blood.htm
