lab 4

CHEM 1001 – 2020, Laboratory #4 1

Name (First & Last): CHEM 1001, Fall 2020, Lab #4: Radiation, Molecules, & Plants

LAB ASSIGNMENT WORKSHEET This is what you will upload to Canvas, as a single PDF file, for your TA to grade.

• Before you get started, please make sure that this file is not opening in a browser and is saved to your computer (documents or desktop).

Part 1: Chromatography – Radiation and Plants This part of the laboratory can be completed prior to lab!

1) Read the Lab #4 background file and watch the videos found in the Assignment tab. 2) In your own words, describe the relationship between chlorophyll and the visible

region of the electromagnetic spectrum. 3) In the diagram below, label the baseline and solvent front. 4) Calculate the Rf values and record your answers in the table below. Do not forget to

show your work! Measure distances from/to the top of each spot.

Spot Rf Value

A

B

C

D

CHEM 1001 – 2020, Laboratory #4 2

5) If you have not yet watched the videos embedded in the “Lab 4: Radiation, Molecules, and Plants” Assignment Tab in Canvas, please do so.

6) After you have watched the videos, type your name below to earn the points. These points are granted on honesty, this is certifying that you have watched the videos:

_____________________________________

Typing my name above confirms that I have watched the Lab #4 videos 7) Below is a chromatogram of a spinach leaf!! Calculate the Rf values for each spot

(dark green, bright green, yellow, red/orange) and record your values in Data Table #1, below. Make sure to include your work to earn full credit!

Data Table #1 – Spinach Leaf Chromatogram, Rf Values

Spot Rf Values Spot Rf Value

Dark Green Yellow

Bright Green

Red Orange

CHEM 1001 – 2020, Laboratory #4 3

Below is Table of Rf Values: Table #1 – Rf Values for Plant Pigments

Pigment Rf (Solvent = 90/10 isopropyl alcohol and water)

carotene 0.94

xanthophyll 0.90

phaeophytin 0.85

chlorophyll a 0.46

lutein 0.37

violaxanthin 0.28

chlorophyll b 0.22

neoxanthin 0.16

chlorophyll c 0.14

8) Which pigments were present in your spinach leaf chromatogram? How can you tell

the pigments were present? Use your data from Data Table #1 and the Rf values in Table #1, to help support your answer.

CHEM 1001 – 2020, Laboratory #4 4

Part 2: Radiation and Molecules This part of the laboratory will be completed in lab. Your TA will put you into a breakout room to explore how different portions of the electromagnetic spectrum interact with various molecules.

1) Use the provided simulation to complete Data Table #2 below, describing how each molecule responds to each category of radiation.

Data Table #2 – Molecules and Radiation

Molecule Type of Radiation

Microwave Infrared Visible Ultraviolet

CO Carbon Dioxide

N2 Nitrogen

CO2 Carbon Dioxide

CH4 Methane

H2O Water

NO2 Nitrogen Dioxide

O3 Ozone

CHEM 1001 – 2020, Laboratory #4 5

2) One of the molecules responds to visible light! Do some research to understand why, how, or what the consequences are of this molecule responding to visible light. In the space below, share what you have found with regards to this molecule absorbing visible light and also include the sources you use to answer this question.

3) Did you notice any patterns or relationships between the molecules that DID

respond to infrared radiation and the molecules that DID NOT respond to infrared radiation?

4) What is the most interesting thing you learned through from this laboratory? Either from Part #1 or from Part #2.

1. Rf ValueA:
2. Rf ValueB:
3. Rf ValueC:
4. Rf ValueD:
5. Typing my name above confirms that I have watched the Lab 4 videos: Wenjia Zhang
6. Rf ValuesDark Green:
7. Rf ValueYellow:
8. Rf ValuesBright Green:
9. Rf ValueRed Orange:
10. MicrowaveCO Carbon Dioxide:
11. InfraredCO Carbon Dioxide:
12. VisibleCO Carbon Dioxide:
13. UltravioletCO Carbon Dioxide:
14. MicrowaveN2 Nitrogen:
15. InfraredN2 Nitrogen:
16. VisibleN2 Nitrogen:
17. UltravioletN2 Nitrogen:
18. MicrowaveCO2 Carbon Dioxide:
19. InfraredCO2 Carbon Dioxide:
20. VisibleCO2 Carbon Dioxide:
21. UltravioletCO2 Carbon Dioxide:
22. MicrowaveCH4 Methane:
23. InfraredCH4 Methane:
24. VisibleCH4 Methane:
25. UltravioletCH4 Methane:
26. MicrowaveH2O Water:
27. InfraredH2O Water:
28. VisibleH2O Water:
29. UltravioletH2O Water:
30. MicrowaveNO2 Nitrogen Dioxide:
31. InfraredNO2 Nitrogen Dioxide:
32. VisibleNO2 Nitrogen Dioxide:
33. UltravioletNO2 Nitrogen Dioxide:
34. MicrowaveO3 Ozone:
35. InfraredO3 Ozone:
36. VisibleO3 Ozone:
37. UltravioletO3 Ozone:
38. Text1: Wenjia Zhang
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