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COPY: Experiment 3: Flame Test and Atomic Spectra

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Last updated almost 6 years ago
19 questions
2
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.
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Read the procedure for Part 1 and record the procedure in your lab notebook (as you would for any pre-lab). Watch the flame test video below, recording all data in the data table. We did not examine the Sodium/Potassium combo or the unknown, so you do not need to record those in your lab notebook.
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1
1
1
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2
2
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2
Add your conclusion to your lab notebook. Remember that you need to reference both parts 1 & 2.
Question 19
19.

Write your conclusion below. Reference both parts 1 & 2.

Question 1
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.

Question 2
2.

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Question 3
3.

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

Question 4
4.

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

Question 5
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.)

Question 6
6.

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.

Question 7
7.

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Question 8
8.

Question 9
9.

Question 10
10.

Answer questions 4 & 6 in your lab notebook. You can skip #5 because we did not test an unknown.
Question 11
11.

How are the electrons excited during flame tests?

Question 12
12.

Question 13
13.

Answer #10 & 11 in your lab notebook.
Question 14
14.

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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.
Question 15
15.

Question 16
16.

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Question 17
17.

Answer #4 in your lab notebook. Remember to reference the backgroun information and your notes to help you with this question!
Question 18
18.

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Answer #6-8 in your lab notebook.
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.
6.17E14
Red wavelength
(m)
4.09E-19
Red Frequency (Hz)
6.91E14
Red Energy (J)
4.57E14
Blue-green Wavelength (m)
7.31E14
Blue-green Frequency (Hz)
4.58E-19
Blue-green Energy (J)
4.10E-7
Blue Wavelength (m)
6.56E-7
Blue Frequency (Hz)
4.84E-19
Blue Energy (J)
4.86E-7
Violet Wavelength (m)
4.34E-7
Violet Frequency (Hz)
3.03E-19
Violet Energy (J)
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.
Orange
Copper
Bright red
Barium
Blue-green
Lithium
Lavender
Calcium
Yellow-green
Sodium
Yellow
Potassium
List the colors of visible light from highest energy to lowest energy.
Blue
Yellow
Violet
Green
Red
Orange
List the colors of visible light from highest frequency to lowest frequency.
Yellow
Red
Blue
Green
Orange
Violet
List the colors of visible light from shortest wavelength to longest wavelength.
Violet
Yellow
Orange
Red
Blue
Green
What particles are responsible for the production of light?
Neutrons
Electrons
Protons
Why do different chemicals emit different colors of light?
Each substance has a different number of electrons.
The temperature of the bunsen burner is different.
The substances have different molar masses.
Be sure to copy the data table in your lab notebook (and give it an appropriate number and title).

Match the color of discharge tube and number of lines to the correct element/compound.

Hydrogen

Helium

Neon

Argon

Bromine

Water vapor

Carbon Dioxide

Mercury
Categorize the definitions/examples to the correct type of spectrum.
Neon Signs
Dark lines on colored background
Bright lines on dark background
Rainbow
Thermal spectrum
Line Spectrum
Continuous Spectrum
Each line in the emission spectra of hydrogen corresponds to an electromagnetic radiation with a specific wavelength.
Match the four observed colors with the correct wavelengths.
Blue
410 nm
Red
434 nm
Purple
486 nm
Green
656 nm
How are electrons excited in this part of the lab?
Electricity is run through the gases which excites the electrons. When the electrons relax, they fall back to ground state emitting radiation in the visible region.
Gases are heated in a Bunsen Burner, exciting the electrons. When the electrons relax, they fall back to ground state emitting radiation in the visible region.
The gases are excited on their own, exciting the electrons. When the electrons relax, they fall back to ground state emitting radiation in the visible region.
It has been calculated that the observed colors in a hydrogen atom correspond to the relaxation of the electron from a higher energy level to the second energy level.
Match the correct color to energy transition (think about how you know which color correponds to the transition).
Green
Blue
Purple
Red