Monica Heard Lab Partner: Brittany Snyder December 4, 2012 Flame Test

Abstract: Many metal solutions were heated over a Bunsen burner and the color of the flame was recorded and the unknowns were found with help from Bohr’s and Planck’s studies. With the chance of error by mixed solutions, mislabeled solutions, or an unclean nichrome wire loop the results are correct although a few outcast colors are shown. The understanding of many things is clear now in how fireworks and computers are made.

Introduction: With Bohr’s study about the relationship between wavelength and an atomic structure of an element, experiments were performed to determine the type of element. An electron can drop to a lower energy level if a spot it opens but not up to a different spot. When an element drops to a lower energy level the energy is lost or emitted. Metal solution heated produces color of the metal burned because the locations of electrons are being changed. The type of metal was found by recording the color when the metal solution was heated. Then the color and metal solution is compared to the known data to find the type it is for the three unknown solutions.

Purpose: The purpose of this experiment is to determine different kinds of metal solutions by using a flame to heat it and record the color emitted and find out why the metal solution is that curtain color.

Procedure: About 10 mL of 6.0 M HCl was put in a beaker and a nichrome wire loop was obtained. The burner was lit and turned to low. The nichrome wire loop was cleaned by rinsing it with distilled water then dipped in 6.0 M HCl. To determine the color the nichrome wire loop should be when clean it was put over the flame. This process was done after every trail for accurate results. The nichrome wire loop was placed in the first metal solution then placed over the flame and the color was recorded. The process was done for all 7 solutions with sodium being last. Then the same process was done but for 3 unknown metal solutions so the color was recorded and the type of solutions was found.

Results: Barium nitrate, lithium nitrate, potassium nitrate, sodium chloride, calcium nitrate, and strontium nitrate substances were all clear. Whereas copper nitrate was a light blue substance. For the unknowns A, B, and C were all clear.

Salt Solution Color

Ba(NO3)2 yellow/green x4 yellow/gold yellow x3 red/orange

Cu(NO3)2 blue/green neon green dark blue light green x2 yellow bright green x2 dark green green

LiNO3 magenta x2 hot pink red x2 magenta/red pink red/pink

KNO3 purple x3 light pink lavender x2 light blue light purple light violet orange NaCl neon orange orange x4 orange/yellow bright orange x3

Ca(NO3)2 Green/magenta/orange orange x2 pink x2 dark purple/blue violet/red/magenta purple/red pink/red

Sr(NO3)2 red/orange neon orange/red pink orange x3 red

Unknown Color A light purple x3 lavender x2 purple x2 light pink sky blue blue B orange x3 orange/red x4

C yellow lemon/lime green yellow/green x3 green

There were no calculations for this lab.

Conclusion: The purpose of this experiment was to determine different metal solutions and figure out why the metal solutions changed to different colors. This was done by using a nichrome wire loop with the metal solution on it and placed it over a Bunsen burner and recorded the results. The purpose was accomplished because the unknown solutions were found with solution A most likely was potassium nitrate because of the color comparison of the flame and solutions, both were clear with a purple flame. Solution B was strontium nitrate based off of the results because solutions B was a dark orange or red and the only other solution with a dark color was strontium nitrate. Solution C was barium nitrate because of the light green and yellow flame and the clear substance it was determined that solution C was barium nitrate. Solution C was also closely compared to copper nitrate but the solution color was a light blue, therefore solution C cannot be named copper nitrate because the solution of this unknown was clear. The process that produces the colors in the flame test is explained by the electrons jumping from one level to another. The electron is gaining energy. The colors of the flame that the metal solutions produced and the lines of the electromagnetic spectrum and very closely related because the colors seen had to be in between about 400nm to 750nm because of the visible light spectrum. This means the colors produced were in between those wavelengths. Discussion: The line spectrum of lithium has a red line at 670.8 nm. The energy of a photon with its wavelength is 2.96 . To calculate frequency the equation used was but first (nanometers) was converted to (meters). Then the energy was found by using the equation . With being and .

Error that could have occurred in this experiment was the metal solutions could have mixed with another solution or the nichrome wire loop could not have been cleaned well. The labeling of the solutions could have also been mislabeled so a different solution was being tested than the label said. These errors are most likely the reason why some outcast colors occur in the results. The error that occurred is unknown but some error did occur because outcast colors showed up in the results. The error that most likely occurred was the nichrome wire loop was not cleaned well. The confidence in the results lowered because of the outcast colors that show in the results but is still at a moderate level. Barium nitrate was a yellow/green color and that is what is should be. When a glass rod is heated it turns yellow which means sodium and barium nitrate are present in the rod. The electrons get excited and produce the color because it is made up of sodium ions. Copper nitrate was green or blue and should have been green/yellow. Lithium nitrates flame was a magenta or pink and should have been a deep red. Potassium nitrate was a light purple flame and should have been a lavender color. Sodium chloride was and should have been bright orange. Calcium nitrate had many different results while it should have been a light orange color. Strontium nitrate was a red/orange and should have been a bright orange with a hint of red. Some of these results differ because of the possible mixture of solutions or unclean nichrome wire loop. Other equipment that could be used if Bunsen burners were not available are matches because a flame is still produce or an alcohol burner, stove or hot plate. The only thing necessary is lots of heat. Metallic salts are used in fireworks for the color affect. When the flame heats the salts it excites the electrons and produces the beautiful colors that we see. The confidence in the results is well because of the number of trials that were done and with only a few outliers the results are well. This experiment helped many understand how things are made with metallic solutions and metals such as fireworks, computers, survival devises. With this understanding many technological advances can and have been made.