Flame Test Lab
Purpose:
1.
2.
3.
4.
5.
Identify the different flame colors produced by different metals.
Compare the flame colors with wavelengths.
Compare the wavelength of different flames to their frequencies and energies.
Explain how the flame colors were produced.
Compare and contrast the results obtained in the lab with regards to colors,
wavelengths, frequencies and energies.
Materials:
1. Bunsen burner
2. Micro-plate
3. Solutions of metallic salts: potassium nitrates, calcium nitrate, barium nitrate, copper
nitrate, lithium nitrate and sodium chloride.
4. 6.0 M HCl
5. Nichrom wire.
Procedures
#1
Obtain a micro plate and add 5 drops of each solution to a different well.
#2
Record on your paper which well holds which solution.
#3
On the larger well, add 10 drops of 6.0M HCL. Be extremely careful, this acid will burn if
It gets in contact with your skin.
#4
Make sure that you have a clean flame test wire. Do this by holding the metal loop in the
hottest part of the burner flame.
#5
The next job is to do your flame tests. Dip the flame test loop into one of the known test
solutions, and hold the metal loop in the hottest part of the burner flame.
#6
Make a table showing the metallic solution and the color of the flame.
#7
Clean the flame test wire, then test another known solution. Keep going until you have
recorded the color of all of the known solutions.
#8
Clean the micro plate by rinsing in water in the sink.
Analysis and Conclusions:
#1
Match each of the colors observed in the flame with the wavelength. Record this
information on your paper.
COLOR
WAVELENGHT (m)
-7
COLOR
WAVELENGHT (m)
Violet
4.22 x 10
Yellow
5.77 x 10-7
Blue
4.69 x 10-7
Orange
6.25 x 10-7
Red
6.98 x 10-7
-7
Green
#2
5.26 x 10
From the table above:
a) Convert all wavelengths from meters (m) to nanometers (nm) using dimensional
analysis. Show your work.
b) Calculate the frequency corresponding to each wavelength. Show your work.
c) Calculate the energy € of a photon corresponded to each frequency. Show your
work.
d) Record all this information in a data table.
Questions
#1
What particles are found in the chemicals that may be responsible for the production of
colored light?
#2
Why do different metals have different characteristic flame test colors?
#3
How is spectrometry used to determine the composition of stars?
#4
The majority of the known compounds tested contain nitrate, yet the colors of the flames
were different. What effect would you expect on the flame colors if these compounds were
chlorides instead of nitrates?
#5
Write the electron configurations of each of the metallic ions tested in the lab.
#6
A fireworks contain copper chloride and lithium sulfate. What colors would you expect to
be produced?
#7
When a pan milk boils over onto the stove the flame turns re-orange. Explain why.
#8
What does a flame test indicate about the energy changes taking place among the
electrons in a metallic ion?
#9
What wavelength corresponds to the visible spectrum? Which color has the shortest
wavelength?
#10 What is the relationship of the colors you saw and the lines of the electromagnetic
spectrum produced by the metals?
#11 When a glass rod is heated, a yellow flame is observed around the point of heating. What
does the yellow flame indicate? Why is it observed when the glass rod is heated?
#12 What other equipment could you use in this investigation if burners were not available?
#13 Neon is a gas that has a reddish-orange emission spectrum. Find out why neon lights
can display a multitude of colors.
#14 Red light has a longer wavelength than the blue light:
a) Which of this color has a higher frequency?
b) Which of this colors the photon has higher energy?