University:
Arizona State University
Course:
CHM 101 | Introductory Chemistry
Academic year:

2024
Views:

107

Pages:

1
Author:

camilobonilladz36

Flame Tests Lab Quiz Flame tests are used to identify the presence of a realatively small number of metal ions. You dip a metal wire into a solution and put it over the hottest part of the flame. This will give off a color showing what elements are present in the compound. What is a flame test? What does it show? How is it done? Atoms emit light when they get excited, then turn to a ground state Under what circumstances do atoms give off light? Why do atoms and emit certain photons. The color of light emitted depends on the of different elements give off different colors of light? energy emitted by each electron returning to the original state. What color are sodium ions in a flame? yellow What color are potassium ions in a flame? violet What effect do chloride compounds have on the colors observed Chloride compounds produce no color, so the true colors of the in flame test? metals being tested can easily be seen. how many metallic ions & nitrates will you be observing? 2 unknowns & 10 ionic compounds Why do different chemicals emit different colors of light? Because all the chemicals have different amounts of energy, frequency, wavelength I think Copper and Lithium was in the unknown. I think this because I saw that the flame was green, yellow, red , and blue. Yellow and Based on the results of your experiments, what metal was found blue could account for the color of the flame. If we eliminate those in your unknowns? Explain. colors, we have green and red. The green could be accounted for by the chemical Copper Nitrate (Cu(NO3)2 and the red can be accounted for by the Lithium Chloride (LiCl). Why do you think the chemicals have to be heated in the flame first before the colored light is emitted? I think the chemicals have to be heated in the flame first because the chemicals need to have a reaction to have a colored light. List the colors observed in this lab from highest energy to lowest energy, highest frequency to lowest frequency, shortest wavelength to longest wavelength Violet, Indigo, Blue, Green, Yellow, Orange, Red. In your own words, write a short explanation on how an electron The electron absorbs the energy in this case it would be the heat absorbs energy and re-emits it as light and why different elements and it re-emits by shooting a photon out to lose their energy when have different spectra. the element is dying. If you test 2 solutions and find that they both produce a red flame, Different elements have different spacing between their ground how can you determine for sure whether they contain the same state and higher energy state. This gives a way to identify elements metal? by their spectrum. what ion determines the color of the flame cation -compounds with matching cations produce the same color flame, anions don't -wavelength of emitted photon are in visible spectrum which are cation (alkali metals, some transition metals) 1/1