Roy1 Baylee Roy Chemistry Honors Mrs. Lyles 26 September 2014 Lab 1 Write-Up: Flame Tests Purpose Determine the Identity of unknown substances using the Flame Test Procedure In this lab you will take a Q-tip and dip it in water then dip it in one of the 10 substance compounds. You will place the Q-Tip in the flame of the Bunsen-Burner by using crucible tongs. After doing so, record the color of the flame in the data table and repeat all the steps for each substance. Then, test the two unknown substances and record their most likely compound. Finally, clean up your station and make sure all materials are put back where they belong. Hypothesis If we test each substance using the flame test, we then will be able to find the unknowns compound by comparing the colors displayed by the reactions. Questions 1) What was unknown #1 and #2? a) #1-Lithium Chloride; The reason being they both had the color of hot-pink. b) #2-Barium Chloride; The reason being they both had the color of a yellowish-green. 2) Is the flame color test a test for the metal or the chloride in each compound? a) The flame color test is a test for the metal within the chloride compounds. 3) Why is it necessary to use a new Q-Tip for each compound?
Roy2 a) It is necessary to use new Q-tips each time so that the compounds don t mix and provide skewed data on the substances. 4) What part of the atom cases the light to be given off? Explain your answer. a) The ground-state of the electrons within the metallic ion because the heat causes the electrons to fall back and emit visible wave lengths 5) Each salt had a different color because the structures of the electron clouds are different for each compound. In which compound did the electrons release the most energy? a) Copper Chloride 6) What would happen if the test compound was a mixture of 2 metals? a) The metal with the highest visible energy would show more than the metal with the lower visible energy level. 7) Looking at the elements in the different families, what is the trend in terms of the colors being produced? a) Going left to right on the periodic table it follows ROYGBIV (in the order of the energy levels). So for example, the s-block section will be a color variety of red and the d-block section will form the colors of yellow, green, and some blue. 8) Extra Credit: How does this lab relate to the real world? a) This lab relates to how they make the colors in fireworks. Conclusion In the following we lab, the purpose was to identify the unknown compounds by using the flame test. In this lab my group and I did so by comparing the colors of the unknown to the known compounds, in which allowed us to categorize the unknown substances. Each substance tested had a different color, or shade of a color. From this information my group and I concluded
Roy3 that the unknown 1 was lithium chloride and that unknown 2 was barium chloride (due to the face that the colors matched up). I learned that the reason the compounds each emitted a different color was because the electrons within the metallic ions were traveling down to the ground state level. I figured this out by putting my knowledge of the movement of electrons and visible light, with the information I gathered from the lab. The lab allowed me to fully understand the movement of electrons on the Bohr Model (the main thing we use in class to describe the movement of electrons to visible light patterns) firsthand. In this way, I put together my experience knowledge and book knowledge. By doing this, it allows you to fully grasp a concept; especially when dealing with science. Aside from the science, this was the first major chemistry lab we have done this year. I learned the actual expectations, deep thinking, pattern catching, and carefulness that you need to have in a lab setting. This is very important and will carry on throughout the rest of the year. Lab Safety In this lab, safety was very important. We had to wear goggles to make sure none of the compounds got in our eyes. We also had to make sure we didn t mix the compounds, because it might have had unknown (and maybe dangerous) reactions. To prevent this we ended up using different Q-Tips for each chemical. Also, we had to clean up the materials and lab counter afterwards to make sure there were no leftover substance pieces. This helps to prevent any future mishaps in labs for the next class.
Roy4 Number Substance Picture 1 Lithium Chloride 2 Sodium Chloride 3 Potassium Chloride 4 Calcium Chloride 5 Strontium Chloride
Roy5 6 Barium Chloride 7 Copper Chloride 8 Cobalt Chloride 9 Unknown 1 10 Unknown 2