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IB Chemistry on Analytical Chemistry, Electromagnetic Radiation and Spectroscopy. Atomic Absorption and Line Emission Spectroscopy
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http://lawrencekok.blogspot.com
Prepared by Lawrence Kok
Tutorial on Analytical Chemistry, Spectroscopy and Line Emission Spectrum
Study on Identification, Structural Determination, Quantification and Separation Involves Qualitative and Quantitative analysis• Quantitative analysis – Amount present in a sample/mixture• Qualitative analysis – What is present/Identity of species in a impure sample/mixture?• Structural analysis – Determination of structure of a molecule• Separation of mixtures – Chromatographic Techniques• Identification of molecules / functional groups• Purity of substances• Composition in a mixture
Analytical Chemistry
Classical method
Analytical Techniques
Qualitative analysis Quatitative analysis
Flame testChemical test
Gravimetric Volumetric Titration
Separation analysis
Melting/boiling point
Precipitation
http://www.glogster.com/joealba/flame-test-lab-post-lab-report/g-6m0d3jrphfhikt976ce4ia0/http://www.chemcollective.org/chem/ubc/exp01
Distillation
Analytical Techniques
Classical method
Instrumental method
Analytical Techniques
Classical method
Qualitative analysis
Quatitative analysis
Instrumental method
Spectroscopy analysis
Separation analysis
Analytical Techniques
Classical method
Qualitative analysis
Quatitative analysis
Chemical test
Flame test
Volumetric Titration
Gravimetric
Instrumental method
Spectroscopy analysis
Separation analysis
Nuclear Magnetic Resonance Spectroscopy
Atomic Absorption Spectroscopy
Ultra Violet Spectroscopy
Atomic Emission Spectroscopy
Infra Red Spectroscopy
Mass Spectroscopy
Paper Chromatography
High Performance Liquid ChromatographyGas Liquid Chromatography
Column Chromatography
Thin Layer Chromatography
• Spectroscopy measures the interaction of the molecules with electromagnetic radiation• Particles (molecule, ion, atom) can interact/absorb a quantum of light
Picture from: http://www.lpi.usra.edu/education/fieldtrips/2005/activities/ir_spectrum/
Spectroscopy
Electromagnetic Radiation
• Spectroscopy measures the interaction of the molecules with electromagnetic radiation• Particles (molecule, ion, atom) can interact/absorb a quantum of light
Picture from: http://www.lpi.usra.edu/education/fieldtrips/2005/activities/ir_spectrum/
Spectroscopy
Electromagnetic Radiation
High Energy Radiation
Gamma/X ray
UV or visible Infra Red Microwave Radiowaves
Low Energy Radiation
• Spectroscopy measures the interaction of the molecules with electromagnetic radiation• Particles (molecule, ion, atom) can interact/absorb a quantum of light
Picture from: http://www.lpi.usra.edu/education/fieldtrips/2005/activities/ir_spectrum/
Spectroscopy
Electromagnetic Radiation
Nuclear spin
High Energy Radiation
Gamma/X ray
Transition of inner electrons
UV or visible
Transition of outer most valence electrons
Infra Red
Molecular vibration
Microwave
Molecular rotation
Radiowaves
Low Energy Radiation
Infra Red Spectroscopy
Nuclear Magnetic Resonance Spectroscopy
Ultra Violet Spectroscopy
Atomic Absorption Spectroscopy
Velocity of light (c ) = frequency (f) x wavelength (λ)• c = f λ• All electromagnetic waves travel at the speed of light (3.00 x 108ms-1)• Radiation with high ↑ frequency – short ↓ wavelength• Electromagnetic radiation has a particle nature and each photon carry a quantum of energy given by
h = plank constant = 6.626 x 10-34 Js c = speed of light = 3.00 x 108ms-1
f = frequency λ = wavelength
hc
E Short ↓ λ, Higher ↑ frequency, Higher Energy ↑
E = hf
Electromagnetic Radiation
Picture from :http://www.azimuthproject.org/azimuth/show/Blog+-+a+quantum+of+warmth
Electromagnetic Radiation and Spectroscopy
Radiowaves Infra Red UV or visible
Electromagnetic Radiation
Electromagnetic Radiation Interact with Matter (Atoms, Molecules) = Spectroscopy
Electromagnetic Radiation and Spectroscopy
Radiowaves
Nuclear spin
Nuclear Magnetic Resonance Spectroscopy
Infra Red
Molecular vibration
Infra Red Spectroscopy
UV or visible
Transition of outer most valence electrons
Electromagnetic Radiation
UV Spectroscopy
Atomic Absorption Spectroscopy
Electromagnetic Radiation Interact with Matter (Atoms, Molecules) = Spectroscopy
Electromagnetic Radiation and Spectroscopy
Radiowaves
Nuclear spin
Nuclear Magnetic Resonance Spectroscopy
• Organic structure determination
• MRI and body scanning
Infra Red
Molecular vibration
Infra Red Spectroscopy
UV or visible
Transition of outer most valence electrons
• Organic structure determination
• Functional gp determination• Measuring bond strength• Measuring degree
unsaturation in fat• Measuring level of alcohol in
breath
Electromagnetic Radiation
UV Spectroscopy
Atomic Absorption Spectroscopy
• Quantification of metal ions• Detection of metal in various
samples
Electromagnetic Radiation Interact with Matter (Atoms, Molecules) = Spectroscopy
http://www.astrophys-assist.com/educate/orion/orion02.htm
Continuous Spectrum :Light spectrum with all wavelength/frequency
Emission Line Spectrum :• Spectrum with discrete wavelength/ frequency • Emitted when excited electrons drop from higher to
lower energy level Absorption Line Spectrum :• Spectrum with discrete wavelength/frequency • Absorbed when ground state electrons are excited
Continuous Spectrum Vs Line Spectrum
http://www.astrophys-assist.com/educate/orion/orion02.htm
Continuous Spectrum :Light spectrum with all wavelength/frequency
Emission Line Spectrum :• Spectrum with discrete wavelength/ frequency • Emitted when excited electrons drop from higher to
lower energy level Absorption Line Spectrum :• Spectrum with discrete wavelength/frequency • Absorbed when ground state electrons are excited
Atomic Emission Spectroscopy
Ground state
Excited stateElectrons from excited state
Emit radiation when drop to ground state
Radiation emitted
Emission Spectrum
Continuous Spectrum Vs Line Spectrum
http://www.astrophys-assist.com/educate/orion/orion02.htm
Continuous Spectrum :Light spectrum with all wavelength/frequency
Emission Line Spectrum :• Spectrum with discrete wavelength/ frequency • Emitted when excited electrons drop from higher to
lower energy level Absorption Line Spectrum :• Spectrum with discrete wavelength/frequency • Absorbed when ground state electrons are excited
Atomic Emission Spectroscopy Vs Atomic Absorption Spectroscopy
Ground state
Excited stateElectrons from excited state
Emit radiation when drop to ground state
Radiation emitted
Emission Spectrum
Electrons from ground state
Absorb radiationto excited state
Electrons in excited state
Radiation absorbed
Continuous Spectrum Vs Line Spectrum
Line Emission Spectra for Hydrogen
Energy supplied to atoms • Electrons are excited from ground to excited states• Electrons exist in fixed energy level (quantum)• Electrons drop from higher to lower, emitting energy of particular wavelength/frequency• Higher the energy level, smaller the difference in energy between successive energy level.• Spectrum will converge(get closer) with increasing frequency• Lines in spectrum converge- energy levels also converge• Ionisation energy can be determined (Limit of convergence)
Atomic Emission Spectroscopy
UV regionLyman Series n=∞ → n= 1
Visible regionBalmer Series n=∞ → n= 2
IR regionPaschen Series n=∞ → n= 3
Line Emission Spectra for Hydrogen
Energy supplied to atoms • Electrons are excited from ground to excited states• Electrons exist in fixed energy level (quantum)• Electrons drop from higher to lower, emitting energy of particular wavelength/frequency• Higher the energy level, smaller the difference in energy between successive energy level.• Spectrum will converge(get closer) with increasing frequency• Lines in spectrum converge- energy levels also converge• Ionisation energy can be determined (Limit of convergence)
Atomic Emission Spectroscopy
UV regionLyman Series n=∞ → n= 1
Visible regionBalmer Series n=∞ → n= 2
IR regionPaschen Series n=∞ → n= 3
Line Emission Spectra for Hydrogen
Energy supplied to atoms • Electrons are excited from ground to excited states• Electrons exist in fixed energy level (quantum)• Electrons drop from higher to lower, emitting energy of particular wavelength/frequency• Higher the energy level, smaller the difference in energy between successive energy level.• Spectrum will converge(get closer) with increasing frequency• Lines in spectrum converge- energy levels also converge• Ionisation energy can be determined (Limit of convergence)
N = 3-2, 656nm
N= 4-2486nm
N= 5-2434nm
N= 6-2410nm
Atomic Emission Spectroscopy
Visible region- Balmer Series
UV regionLyman Series n=∞ → n= 1
Visible regionBalmer Series n=∞ → n= 2
IR regionPaschen Series n=∞ → n= 3
Atomic Emission Spectra• Energy supplied• Electrons surround nucleus in allowed energy states (quantum)• Excited electron returning to lower energy level, photon of light with discrete energy/wavelength(colour) will be given out.• Light pass through a spectroscope, with a prism to separate out different colours• Line emission spectra is produced.
Line emission spectra for different elements can be found here
Acknowledgements
Thanks to source of pictures and video used in this presentation
Thanks to Creative Commons for excellent contribution on licenseshttp://creativecommons.org/licenses/
Prepared by Lawrence Kok
Check out more video tutorials from my site and hope you enjoy this tutorialhttp://lawrencekok.blogspot.com