Peter Jeschofnig, Ph.D. Version 42-0160-00-01
Lab RepoRt assistant
This document is not meant to be a substitute for a formal laboratory report. The Lab Report Assistant is simply a summary of the experiment’s questions, diagrams if needed, and data tables that should be addressed in a formal lab report. The intent is to facilitate students’ writing of lab reports by providing this information in an editable file which can be sent to an instructor.
obseRvations
The color of the flame is expected to be as follows:
Metallic ion Flame color
Sodium Na+
Strontium Sr2+ Potassium K+ Lead Pb2+ Barium Ba2+ Copper Cu2+ Lithium Li+ Calcium Ca2+ Unknown
Questions
A. All chemical used in this test are binary compounds. What portion of the periodic table is responsible for the color observed? The metals are responsible for the Color change
B. In cooking over an open flame, a yellow flame is often observed when some food is spilled into the flame? What is most likely responsible for the yellow flame color?
Sodium within the food is likely the cause of this color change. The reason for this assumption is that during this flame test sodium changed the flame to a yellow color
C. What problems might be associated with using flame color for identification purposes? The cotton swab or the Well plate may be contaminated if not cared for properly. You may also have not soaked the cotton swap enough to allow the chemical to be burned and you are burning the cotton swab itself and cause you to have false results. Also you may have a difficult time noticing the actual color change of the flame.
D. Explain how the observed colors are produced?
As the substances are heated, the electrons move to higher energy levels by absorbing the heat. This state is unstable and the electrons tend to return to their ground state and release the absorbed heat energy in the form of electromagnetic energy. A portion of this energy