Flame Test Lab Handout
FLAME TEST Lab Pre-Lab Questions ( questions and answers go in lab book)
1. What is the velocity of light?
2. Using f = v
rearrange the equation to solve for 𝜆 (using algebra).
𝜆
3.
How many nanometers are in 1 meter?___________
4. Can you use nm or m in the equations?
5. Which equation do you use to calculate the amount of energy in different types of light?
6. How do you find the wavelength of blue colored light?
7. Which color light is closest in frequency to ultraviolet light?
8. Which color light is closest in wavelength to infrared light?
Equations:
f=v
λ
Violet
E = hf
Blue
c = 3.00 x 108 m/s
E = hc
λ
Green
Yellow
h= 6.626x10-34 J∙s
Orange
Red
Chemistry Flame Test Lab
1. Introduction: The flame test is used to visually determine the identity of an unknown metal ion based on the color the metallic
salt turns the flame of a Bunsen burner. When metals are exposed to high temperatures, electrons transition to a higher energy level
(the excited state), and after, the return to the ground state while simultaneously emitting a photon. The color of this photon, in the
visible spectrum, allows us to say if a metal cation is copper or potassium, for example.
2. Materials: calcium, strontium, barium, lithium, sodium, potassium, copper, and 2 unknown salt samples in cups with the ion name
written on the side (9 cups total), Bunsen Burner, 20 Q-tips soaked in water per group, goggles, lab book.
3. Directions:
A)
B)
C)
D)
E)
F)
Complete pre-lab question on front.
Write this lab up in your composition book using this handout as your guide.
On lab day, tie back hair and roll up sleeves. Goggles must be on at all times.
In your group, gather your sample ion cups including the 2 unknowns
Light the Bunsen burner.
Take a wet Q-tip and dip into sample cup. Put Q-tip in the blue part of the flame and observe the color. Write the color
down on your lab book DATA TABLE. Throw Q-tip away.
G) Repeat step F until all samples have been tested. Use a clean Q-tip each time so your samples don’t get contaminated.
Repeat tests when done
4. LAB DATA TABLE: Fill in the data table below with the expected color before the lab and the observed color as you do the lab.
Complete the rest of the table after you have made your observations.
Sample #
Ionic
Compound
1
Ca(NO3)2
2
Sr(NO)2
3
Ba(NO3)2
4
---
5
LiNO3
6
NaNO3
7
KNO3
8
---
9
Cu(NO3)2
10
NaCl
Expected Color of
Flame
Observed
Color of
Flame
Observed λ
(nm)
Observed
λ (m)
Observed
f (Hz)
---
---
---
---
---
---
Observed
E (J)
5. Questions to discus in your conclusion:
1.
2.
3.
4.
How can flame tests be use to identify an element?
Street lights that burn yellow, most likely contain what metallic ion?
In some of your experiments above, you may not have observed the expected color of the flame. What are some reasons that
might account for this?
How do you think scientists are able to determine what elements stars are made of by studying the color spectra of different
stars?