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.

Source: http://www.chemguide.co.uk/inorganic/group1/flametests.html

 

Video of flame test

 

http://www.youtube.com/watch?v=EbkLp3-o78E

 

 



 

 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.