Acc. Chem- Mr. Tuttle
Flame Tests and Emission Spectra Lab Summary
Name | Color |
Calcium Nitrate | Orange |
Barium Nitrate | Faint Green |
Sodium Nitrate | Yellow |
Strontium Nitrate | Bright red, orange |
Unknown (Lithium Nitrate) | Dark Red |
Copper Nitrate | Green |
Lithium Nitrate | Scarlet Red |
Potassium Nitrate | Purple |
1) Which elements gave the most easily identifiable colors? Which gave the least easily identifiable colors? Why?
The most easily identifiable colors were Copper Nitrate, and Potassium Nitrate. They had unique easily identifiable colors like Sodium Nitrate had a bright yellow, Copper Nitrate had a goblin green, and Potassium had a purple hue. Calcium (orange), Barium (light green), Strontium (red, orange), the ...view middle of the document...
This is because both the unknown substance and Lithium gave off a dark/scarlet red. The next closest guess would be strontium but that was more of a red orangish color so it was eliminated as a choice. In general, it could but not all the time because some metal ions donâ€™t emit color when reacting with flames but if you had two that did then yes you could.
4) Do you think flame tests are useful in detecting metal cations present in a mixture of metal ions? Explain your answer.
No because it isnâ€™t very accurate. Some of the metal cations have similar colors and also some metal cations don't even emit color during the flame test.
5) What is the purpose of the cobalt blue glass in identifying sodium and potassium?
Cobalt blue glass is used to block out yellow light from the flame and off the metal so that you can get a better look at the exact color of the flame.
6) Apple wood often burns with a green flame. What element(s) might be present in the wood? Can you think of a way to test this hypothesis?
The elements present in apple wood could either be Copper Nitrate or Barium since when they react with fire they produce a greenish hue. One way to test this would be burning some calcium nitrate and comparing it with burning apple wood.
1) Identify each element by comparing your observed spectra with the spectrum charts in the lab and your textbook.
2) Can emission spectra be used to identify gaseous elements? Explain your answer.
Yes because the way emission spectrum works is that when an atom moves from a high-energy state to lower it releases electromagnetic radiation. Atoms have their own unique amounts of electromagnetic radiation and so it can be used to identify any type of elements as well as gaseous.