Flame Test Lab

NaCl + flame:

Alison and me in our natural habitat (because were hot like this flame):

The purpose of this lab was to explore the fact that energy levels of elements are quantized. To demonstrate this we conducted a series of flame tests by placing wooden sticks that had solutions of different compounds over the flame of a bunsen burner. Different colors of flame were produced due to the different metals in the compounds.

Questions:

1) What is the difference between ground state and an excited state?

Ground state is the lowest energy level that an atom or ion of an element can be, and has the normal, most stable electron configuration. An excited state is said to be unstable, when electrons of an atom or ion absorb energy and jump to a higher energy level.

2) What does the word "emit" mean?

"Emit" means to produce or discharge. For example, if a compound emits a red color when heated, it produces a visibly red color when heated.

3) In this experiment, where are the atoms getting their excess energy from?

The atoms are getting their excess energy from the heat of the flame of a bunsen burner.

4) Why do different atoms emit different colors of light?

The energy of each atom is quantized and each atom has a certain number of electrons, therefore only a certain color will be emitted by a compound.

5) Why is it necessary to clean the nichrome wires between each flame test?

The flame will react with all metal elements present, so not cleaning the wires could produce unwanted results. Therefore, the wires need to be cleaned to remove metal from previous trial(s).


Identity of Unknown #1: LiCl

Identity of Unknown #2: KCl


We found the identities of these unknowns by comparing the colors of the flames they emitted to the other solutions. Unknown #1 produced a vivid red color, like the LiCl. Unknown #2 produced a purple color with specks of red, like the KCl.