Quantized Energy Levels

Below is a lab report for an experiment I did in my Chemistry Class to understand what quantized energy level is.

Procedure:

  1. Light the Bunsen burner (turn the gas on so you can just hear it, then use the striker)
  2. Place the wood splint for each compound into the flame using tongs or tweezers- ONE AT A TIME!
  3. Take note of the color of the flame and return the wood splint to the solution.
  4. CLEAN UP YOUR STATION! Carefully put the stoppers back on the solutions! Make sure the station looks like it did when you started! Let me know if you need new splints!
  5. Wash your hands thoroughly before leaving the laboratory

 

Pre-lab questions

  1. We see colors in the flame tests because different color means different energy emitted.
  2. We will test the substance qualitatively by burning the salt and judge the color with our eyes. We can then use the wavelength corresponding to the color to quantify the data.

 

Data Table: make a section of your lab labeled Data Table and make a data table similar to the one below to record your observations.

Compound Color of Flame (qualitative) Wavelengths of light (in Å) (quantitative)
Barium Chloride Yellow 570-590nm
Calcium Chloride Light Red 620-750nm
Copper (II) Chloride Green 495-570nm
Lithium Chloride Red 620-750nm
Potassium Chloride Orange 590-620nm
Strontium Chloride Red 620-750nm
Unknown #1    

 

Discussion and Analysis: (In a section labeled Discussion and Analysis answer the following questions in complete sentences)
How do your results from the flame test provide support for quantized energy levels? Explain your answer.
When exposed to flame, electrons move from one orbital to another, which then cause the photon emitted to have different energy levels, or in other words, different wavelengths. And colors result from light traveling at different wavelengths. By looking up the wavelength corresponding to each color, we can write our data in a quantifiable manner.

 

Conclusion: (answer in a complete paragraph and in complete sentences) What are two possible sources of error for this lab. How would the errors affect your lab? What would you do differently next time to counteract these errors?
One possible source of error can be my judgment of the color of the flame. This can significantly affect the result of the lab because it’s the basis of how I got the wavelengths of light. Next time, I can just take pictures, measure the color codes and find the wavelengths in a more accurate manner. Another source of error can be the time at which I record the data. The color of the salt changed as I let it burn. If I recorded data at different times, the color will change and the data won’t be accurate. Next time I will record the data after 3 seconds for all types of salt.

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