Name ______________________________
Date_______________________________
Flame Test Lab
(Formal Write-up)
Materials:
8 watch glasses
1 beaker
1 plastic pipette
15 mL of ethyl alcohol
A small sample (see demo) of each of the seven known metals
A small sample of the unknown salt mixture (2 unknown metals)
Bunsen burner
Piece of paper to place under and distinguish the 8 samples
(Your safety goggles should already be on!!!)
Procedure:
(Note: Everything that you obtain MUST be properly returned to that same place before you can
leave the lab)
1.
2.
3.
4.
5.
Obtain 8 watch glasses
Obtain your 8 metal samples (7 of which you will know the identity, and 1 will be an
unknown mixture). Devise a system in which you will label/identify the contents of
your 8 watch glasses (see “materials” section for ideas)
Take your beaker and measure (approximately) 15 mL of ethyl alcohol
Using your plastic pipette at your lab bench, pipette approximately ONE pipette full of
ethyl alcohol into each of your 8 watch glasses, being careful not to touch the pipette
to any of the solids.
Light your Bunsen burner.
6.
7.
Using standard and proper safety techniques, take your Bunsen burner and light (one
at a time) each of your 8 watch glasses. (See demo for proper technique) Be careful
not to touch the tip of the Bunsen burner into the alcohol. Record all observations,
taking particular notice in the exact color(s) of the flame that you see as well as what
your solid looks like (before vs after). Repeat this for all 8 of your samples.
(Recording all observations is very important for determining the identity of your
unknown.) All observations will become part of your “Data and Observations” section of
your write-up.
Clean your watch glasses and return all items where they belong before leaving your
work area.
Questions:
(Remember, one of the things that you are trying to determine is what is taking place during the
flame test whereby various colors of light are being emitted.)
1.
2.
3.
4.
5.
Why do different chemicals emit different colors of light?
Why do you think the chemicals have to be heated in the flame test first before the
colored light is emitted?
Colorful light emissions are applicable to everyday life. Where else have you observed
colorful light emissions? Are these light emission applications related? Explain.
What is the characteristic flame color for lithium, calcium, sodium, barium, zinc,
copper, and potassium? Explain why.
Conclude what metals were present in your unknown. Explain how you came to this
conclusion. Is using a flame test the only or best way to conclusively determine a
mixture of metals? Explain.
(REMEMBER: When doing the formal lab write-up, make sure ALL sections are included and that
you have a separate conclusion section, even though you have questions to answer as well.)