Spectroscopy Lab Report

cName Nicholas CasselGen Chem 1210 23 March 2013 Blinded By the set out Abstract In this experiment we were provided a food grain boxwood mass spectrometer to observe the emanation makes of terrific gases and heat content. Based on the surpass readings on the spectrometer and the Balmer-Rydberg formula, their wavelengths and percent shift were cap competent to be extrapolated. Based on the literature values, the cereal box spectrometer proved its value as a decently accurate spectrometer. Introduction Every portion and attendant atom associated emits take fire also know as electromagnetic radiation, when in an excited state.Analyzing this emitted gentle sewer give insight to the makeup and characteristics of them. The light given off by an energetically excited atom is not a continuous distribution of all possible wavelengths, but quite a consists of a few wavelengths giving a series of discrete terminations. spectrum analysis is the analysis of that emitted light an d its dispersion into to its component wavelengths and colors. Niels Bohr explained the discrete spectrum of hydrogen? by relating it to the electron. Normally the electron in the hydrogen atom is locate in the prototypic energy-level.When a hydrogen atom atoms gains energy, the electron moves from a lower energy-level to one of higher(prenominal) energy. The energy gained by the atom is incisively the amount of energy needed to move the electron from the lower energy-level to the higher energy-level. With its electron in a higher energy-level, the atom is now in an unst able, higher energy, excited state. The tendency is for electrons to occupy the lowest level avai lable. So shortly after gaining the energy, the electron returns to a lower energy-level. Energy must be given up when this occurs, and the energy is lost as light.Each pull back in the emitted light of hydrogen represents the movement of an electron from a special outer level to a specific inner one. We judge thi s emitted light against the electromagnetic spectrum with a spectrometer. A spectrometer is an instrument that gathers light particles (photons) and is able to determine the chemical make-up of the source. A spectrometer breaks up a beam of light into its component colors. Usually it uses a prism or a diffraction grating. Light goes in as a beam of uninfected light and is split into a rainbow. Particular atoms generate light at particular frequencies (colors) and so can be identified in the lab.The electromagnetic spectrum is the range of all possible wavelengths of electromagnetic radiation. This range extends from sub-radio waves to gamma rays. megascopic light falls within this spectrum. The light emitted by each element is independently different and has different colors that can be bumpn on the spectrum. The Balmer-Rydberg formula is used to describe the emission lines of hydrogen across the wide-cut spectrum and not just visible light. The purpose of this laboratory experi ment is to see the emitted wavelengths of elements through a spectroscope and calculate the wavelengths with the Balmer-Rydberg formula.Then with the calculations, relate them to the atom. I consider that with the localise calculations and comparisons the wavelengths, each emission line will be able to be determined. Experimental The procedures as per the lab manual page 258 (Grossie, Underwood, 2012) were to first calibrate our spectroscope with helium. Looking at helium through the spectroscope, the emission lines where seen and recorded. That entropy was hence put into Microsoft Excel and put into a represent. From the graph a formula was extrapolated. The spectroscope was used to observe and record the fours phantasmal lines of hydrogen.The calibration plot from helium determine the wavelengths of each of the lines by extrapolation. analyze the calculated wavelengths to those determined from the calibration plot, and thusly(prenominal) calculate the percent misplay for the values. Then the spectroscope was used to suppose the spectral lines of argon, krypton, neon and Xenon. These noble gasses are then calculated in the same manner as hydrogen. Data Results The wavelengths (? ) for helium for the calibration were given to us in our lab manual on page 261 (Grossie, D. , et al. 2012). With the spectroscope, the helium in the discharge vacuum tube was observed. The emission line scale eading and colors were then recorded on table 1. 1 which can be found below. These values where then put into an excel spreadsheet and graph was formed (table 1. 2). An equation was then extrapolated from the data that would give the experimental wavelength (expt ? ) values that will be used for after values. The apparent motion line for table 1. 2 was established to see the affinity between wavelength and scale readings. Expt ? =a ? +b Expt ? =7. 1541 ? + 343. 12 TABLE 1. 1 Helium Calibration ? (nm) Scale Reading assumption 667. 8 45 rose-cheeked 587. 6 35 Yellow 501. 6 22 young 492. 2 20 blue(a)-green 471. 3 18 Blue 47. 1 15 empurpled TABLE 1. 2 Helium Calibration graph Then, by measuring and calculative the emission lines in the hydrogen line spectrum, the data on table 1. 3 was collected. The calculated wavelength (Calc ? ) was determined by the Balmer-Rydberg formula. 1? =R(1m2-1n2) R=Rydberg constant quantity=1. 0968x107m-1 The percent flaw was then calculated by the following equation. mistake %=(calc ? -expt ? )calc ? The experimental wavelength (expt ? ) was determined with, Expt ? =7. 1541 ? + 343. 12 TABLE 1. 3 Hydrogen arc Scale Reading Color Expt ? m n Calc ? ? % misapprehension 1 2 1 3 1 4 45 Red 665. 05 2 3 656. 11 1. 36 26 light-green 529. 12 2 4 486 8. 87 13 Blue 436. 12 2 5 433. 94 0. 5 29 Indigo 550. 58 2 6 410. 07 34. 26 3 4 3 5 3 6 The measuring and calculating of the emission lines in the Neon, Argon, Krypton and Xenon line spectrums yielded the data on tables 1. 4-1. 7. The calc ulated wavelength (Calc ? ) was determined by the Balmer-Rydberg formula. 1? =R(1m2-1n2) R=Rydberg Constant=1. 0968x107m-1 The percent error was then calculated by the following equation. error %=(calc ? -expt ? )calc ?The experimental wavelength (expt ? ) was determined with, Expt ? =7. 1541 ? + 343. 12 TABLE 1. 4 Neon run Ne Scale Reading Color Expt ? Calc ? % error 45 Red 665. 05 640. 2 3. 88 38 Orange 614. 97 607. 4 1. 24 35 Yellow 593. 51 588. 2 0. 9 27 Green 536. 28 540. 1 0. 7 TABLE 1. 5 Argon Emission Ar Scale Reading Color Expt ? Calc ? % error 10 Violet 414. 66 454. 6 8. 78 32 Yellow 572. 05 514. 5 11. 18 54 Red 729. 44 528. 7 37. 96 TABLE 1. 6 Krypton Emission Kr Scale Reading Color Expt ? Calc ? % error 30 Green 557. 74 476. 3 17. 09 13 Violet 436. 12 406. 7. 31 15 Blue Violet 450. 43 415. 4 8. 43 34 Yellow 586. 35 520. 8 12. 58 TABLE 1. 7 Xenon Emission Xe Scale Reading Color Expt ? Calc ? % error 21 Green 493. 35 513. 1 3. 84 18 Blue 471. 89 464. 3 1. 63 Disc ussion The helium trend line in table 1. 2 shows that as the longer the wavelength gets, higher the scale rating becomes. This is because the longer the wavelength is, the less energy it has. The emission lines of hydrogen were then observed and recorded on table 1. 3 with the scale readings. The m and n levels were already given to us on the table front to the beginning of the lab.Using the Balmer-Rydberg formula, the wavelength could be calculated. Using the calibration of helium, the experimental calculation was able to be determined with the equation extrapolated from excel. The two results gave rise to the error calculations. equivalence the hydrogen results with tables 1. 4 1. 7, its can be seen that there is a trend of the longer the wavelength is, the more percent error there is. Through our cereal box spectrometers, the emission lines of the low energy waves viewed a the color scarlet are more broad than that of the high energy waves because theirs are oft longer respe ctively.This makes it more difficult to determine the exact scale reading. With the correct calculations as proposed, each emission line was able to be determined. consequence The ability to observe emission lines then decipher the element is a useful application in the fields of astronomy. Astronomers are able to view the emissions and determine the chemical make up of a specific design billions of miles away. The data collected indicated that as the lower the energy of the waves, there was a error percentage. This error is also from a cereal box spectrometer.It can be inferred that there is an inherent amount of decreased precision in assessing the scale readings. Future experiments could mum make use of the cereal box but also have a laboratory quality spectrometer to compare accuracy too. There could be significant human error in the construction of the cereal box versions. The results of this experiment, bar any inaccuracy, where still in line of the calibrated helium. Refer ences Grossie, D. & Underwood K. (2011). Laboratory Guide for Chemistry. nuclear Spectrometry, Wright State University. Dayton, OH.