Thursday, November 7, 2013

Flame test experiment

Kristin Bethea
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
Ba+ Cl
Green color
Calcium Chloride
Ca+ Cl
Orange color
Lithium Chloride
Li+ Cl
Brick red color
Potassium Chloride
K+ Cl
Lilac color
Sodium Chloride
Na+ Cl
Yellow color
Strontium Chloride
Sr+ Cl
crimson color
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
 
 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.
 
      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.