Sunday, September 29, 2019

Flame Test Lab

Flame Test Lab Question: When a compound is placed in the flame of a burner, what happens to the color of the flame? Hypothesis: When the compound is placed in the flame, the flame changes color depending on the chemical compound. When they’re heated, they gain energy and changed color sometimes. Safety Requirements for this Lab: Wear goggles at all times. If you want to remove them to write in your notebook you may sit at a table in the center of the room. When you sit down remove them and when you stand up put them on. Use aprons. Pull back hair. No loose clothing.Close-toed shoes. NO FOOLING AROUND. It is very important that you DO NOT mix up the nichrome wire hands. Background Information: When chemical compounds are heated, hey gain energy. The electrons in some of these chemicals will jump from their ground state electron configuration (such as the electron configurations we have ben drawing for the elements) to higher energy levels. As these electrons fall back to their original positions in the atom, they emit energy. One form of this energy is light energy. This is what you will be observing in this experiment. Materials: Nichrome wire wand  · Test tubes containing water  · Test tubes containing 6M hydrochloric acid as needed to clean wire  · Test tubes containing: Copper sulfate Potassium sulfate Copper nitrate Potassium nitrate Strontium nitrate Calcium nitrate Copper chloride Strontium chloride Calcium chloride Cobalt chloride Sodium chloride Sodium nitrate Sodium sulfate Barium clroride Calcium nitrate  · Tirrel burner  · Matches  · Goggles  · Apron Procedure: Work in teams of two At each table there are two samples and two tirrel burners and matches.Start the burner as you have learned to do and obtain a low blue flame with the inner blue flame. Next take the nichrome wire and place in the flame. Noticed its color when it becomes red hot. This is not the color of the flame you are looking for. The flame to observe is the one o btained just as you place it in the flame. Place the wand in the test tube with the solution of the compound, quickly place it in the flame and observe its color. Write down the color and any observations on the table provided below. Do this no more than three times.Then rinse the wire in the water Heat the wire in the flame until it has no residue from the compound left. If you have problems ask your teacher. Return the nichrome wire to the water test tube. When this is completed, exchange chemical compound setups with you tablemates. Repeat the procedure for each chemical compound. When your table is done with both chemical compounds, pass them both clockwise to the next table. When all chemical setups are complete, the class will discuss which chemical compounds that you would like to observe again.Analysis: Each element is made up of different atoms. The heat helps the atoms move around and emit different colors of flame. Only certain elements can be identified by the naked eye. With others, you can identify an element by their colors, or if a metal, by their hardness and durability. I do not believe it would be effective because some elements might be similar in most ways and have you confused. I think if the wire in this lab became contaminated, the results of the flame would be different.The colors of the flame would not be correct due to the contamination and chemical compound on the wire. All of the flames don’t have the same color because each chemical on the wire is different. It has to have a boost to a higher energy level. Once they’ve fallen baxck to their first positions, they emit energy. The color of the flame is caused by the exciting metal ions. They are shown once burned just like we did in class. Copper: 1s22s2 2p63s23p64s23d9 , Sodium: 1s22s2 2p63s1 , Potassium: 1s22s2 2p63s23p64s1 , Strontium: 1s22s2 2p63s23p64s23d104p65s2 Flame Test Lab I. Purpose: To observe the colors produced when compounds are introduced into a flame and the electrons become excited. To estimate the wavelength of light produced, then calculate the frequency and energy of the light II. Safety: Standard safety procedures III. Chemical Inventory: Chemical Name: |Hazards: | |Lithium Chloride |Moderately | | |Toxic by ingestion | |Potassium Chloride |Slightly toxic by ingestion | |Calcium Chloride |Slightly toxic | |Barium Chloride |HIGHLY toxic by ingestion.Use extreme caution | |Cupric Chloride |HIGHLY toxic by ingestion. Use extreme caution | IV. Pre-Lab Questions: V. Procedure: 1. Dip the soaked wooden splint in one chemical at a time. Make a few crystal stick to the splint 2. Hold the end of the splint with the crystals in the burner flame and watch the first color you see. When it changes to orange, the splint is burning and we don’t care about that color 3. Use your chart from your prelab to estimate the wavelength of the color being produced 4. Obtain an unknown from your teacher, record the letter of the unknown, and do a flame test on the unknown. It will be one of the chemicals you have already tested. VI. Data and Observations: Chemical |Color produced |Estimated Wavelength (nm) | |Lithium Chloride | | | |Sodium Chloride | | | |Potassium Chloride | | | |Calcium Chloride | | | |Strontium Chloride | | | |Barium Chloride | | | |Cupric Chloride | | | |Unknown___ | | | VII. Calculations: For each chemical, do the following calculations. 1. Using the estimated wavelength, calculate the frequency of the light produced. 2. Using the frequency of the light, calculate the energy of each photon of light produced. VI. Conclusion: VIII. Error Analysis:

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