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Experiment 3: Flame Test and Atomic Spectra

Last updated over 5 years ago
13 questions
Note from the author:
AP Chemistry level lab on Flame Tests & Atomic Spectra
This lab will be a little different than prior labs. You will be completing the lab virtually. You will still complete the lab in your lab notebook (to ensure that you have record of the lab) like you have before, but you will be answering all of the lab questions here.

Here is how you will complete the lab:

1. Read the background information below (or in the lab handout here: https://docs.google.com/document/d/10Me2VnpmUpWEfBoFQ8nat2Cus6Da7sPcLhx0-gScCMA/edit?usp=sharing). In the background information you will find the purpose. Record the purpose of the lab in your lab notebook.

2. Complete the rest of your pre-lab in your lab notebook (procedure for both days and pre-lab questions).

3. After you complete the pre-lab questions in your lab notebook, answer the questions here to recieve credit.

4. Watch Part 1 of the lab. As you watch the video, record your data & observations in a data table in your lab notebook. (This will be in your data & observations section of your notebook.)

5. Complete Part 2 of the lab. This will require you to observe pictures of gas discharge tubes and the corresponding emission spectrum. Fill in your data table in your lab notebook. Again remember to label your each data table appropriately and use a ruler or straight-edge.

6. Work through the post lab questions for both part 1 and part 2. Answer the post lab questions in your lab notebook and then answer certain questions here to receive credit.

7. Finally, write your conclusion (purpose, was it fulfilled, why or why not) in your lab notebook. Then transfer it here to receive credit.

As you work through the lab, send any questions through email or Remind.
1

Read the background information to review light and waves, as well as to find the purpose of the lab. Check below once you've read it.

3

Calculate the corresponding wavelength (in m), frequency (in Hz), and energy (in J) associated with each line in the table. Match the appropriate value with each label.2

Remember to fill in the table in your pre-lab as you complete the prelab. Show work in your lab notebook for one of each calculation.

Draggable itemCorresponding Item
4.09E-19
Red wavelength
(m)
4.10E-7
Red Frequency (Hz)
6.91E14
Red Energy (J)
7.31E14
Blue-green Wavelength (m)
4.86E-7
Blue-green Frequency (Hz)
6.17E14
Blue-green Energy (J)
4.57E14
Blue Wavelength (m)
4.34E-7
Blue Frequency (Hz)
3.03E-19
Blue Energy (J)
4.84E-19
Violet Wavelength (m)
6.56E-7
Violet Frequency (Hz)
4.58E-19
Violet Energy (J)
0.5

Calculate the energy of this photon (in J). Give your answer to 3 SF.
Only include the number. You can use the format 3E-10 or

0.5

Convert this energy to kJ/mol.
Only give the numeric answer.

0.5

The ionization energy of sodium is 496 kJ/mol. Would light with a wavelength of 400 nm be sufficient to cause sodium to lose its electrons? Explain why/why not.
(Hint: You just calculated the energy in kJ/mol for 400 nm light.)

0.5

Calculate the minimum wavelength of light (in nm) that would be needed to cause a single sodium atom to lose an electron.
Give only the numeric portion of the answer.

Watch the flame test video below, recording all data in the data table.
3

Be sure to copy the data table in your lab notebook (and give it an appropriate number and title).

Match the correct colors to metal ions.

Draggable itemCorresponding Item
Blue-green
Copper
Yellow-green
Barium
Orange
Lithium
Yellow
Calcium
Bright red
Sodium
Lavender
Potassium
1

List the colors of visible light from highest energy to lowest energy.

  1. Orange
  2. Blue
  3. Violet
  4. Yellow
  5. Green
  6. Red
1

List the colors of visible light from highest frequency to lowest frequency.

  1. Orange
  2. Violet
  3. Red
  4. Blue
  5. Yellow
  6. Green
1

List the colors of visible light from shortest wavelength to longest wavelength.

  1. Red
  2. Yellow
  3. Green
  4. Violet
  5. Blue
  6. Orange
Answer questions 4 & 6 in your lab notebook. You can skip #5 because we did not test an unknown.
1

How are the electrons excited during flame tests?

1

What particles are responsible for the production of light?

1

Why do different chemicals emit different colors of light?

Answer #10 & 11 in your lab notebook.
As you work through the part 2 post lab questions (answering in your lab notebook as well), remember that the background provides lots of information that will be useful for these questions.