Lab 7: Flame Test Lab

In this lab, we had to burn different compounds over a flame with a wooden stick and observe the color of light emitted.  We then used those recordings to identify two mystery chlorine compounds in the end.

Pre-Lab Questions:

1.  The ground state is the normal electron configuration of atoms or ions of an element, whereas the excited state is when atoms or ions in the ground state are heated to high temperatures and some electrons absorb energy and "jump" to a higher energy level.

2.  The word "emit" means to release.  Electrons emit light in the form of electromagnetic radiation as they return to ground state.

3.  In this experiment, the atoms are getting their excess energy from the bunsen burner flame, since the atoms are being heated at high temperatures, causing the electrons to absorb energy and jump to higher energy levels.

4.  Different atoms emit different colors of light because each atom will produce only one color (each atom is quantized).  Different atoms also have different electrons, and those electrons could jump to different energy levels, creating different colors.

5.  It's necessary to clean the nichrome wires (or, in this experiment, use a different stick each time) between each flame test to ensure that different compounds don't mix.

Unknown #1 was lithium chloride (LiCl) and unknown #2 was potassium chloride (KCl).  We found this because we compared the color burned to the other eight recorded color observations.  Unknown #1 burned a magenta color, shown above, which matched LiCl, and unknown #2 burned a light purplish color, which matched KCl.