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- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Molecular_and_Atomic_Spectroscopy_(Wenzel)/6%3A_Atomic_Spectroscopy/6.2%3A_Atomization_Sources/6.2C%3A_Specialized_Atomization_MethodsOne design of a cold vapor system consists of a closed loop where there is a pump to circulate air flow, a reaction vessel, and a gas cell. The sample is placed in the reaction vessel and all of the m...One design of a cold vapor system consists of a closed loop where there is a pump to circulate air flow, a reaction vessel, and a gas cell. The sample is placed in the reaction vessel and all of the mercury is first oxidized to the +2 state through the addition of strong acids. When the oxidation is complete, tin(II)chloride is added as a reducing agent to reduce the mercury to neutral mercury atoms.
- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Molecular_and_Atomic_Spectroscopy_(Wenzel)/4%3A_Infrared_Spectroscopy/4.3%3A_Fourier-Transform_Infrared_Spectroscopy_(FT-IR)An important thing to recognize in drawing these plots is that, if the mirror is at –½x, the radiation that goes to the moveable mirror travels an extra distance x compared to the radiation that goes ...An important thing to recognize in drawing these plots is that, if the mirror is at –½x, the radiation that goes to the moveable mirror travels an extra distance x compared to the radiation that goes to the fixed mirror (It travels an extra ½x to get to the moveable mirror and an extra ½x to get back to the zero position).
- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Molecular_and_Atomic_Spectroscopy_(Wenzel)/3%3A_Molecular_LuminescenceAmong luminescent methods are various sub-categories that include the processes of fluorescence, phosphorescence, chemiluminescence, bioluminescence and triboluminescence. Among these different sub-ca...Among luminescent methods are various sub-categories that include the processes of fluorescence, phosphorescence, chemiluminescence, bioluminescence and triboluminescence. Among these different sub-categories, fluorescence spectroscopy is by far the most common technique used for analysis purposes. You are no doubt familiar with fluorescent lights. This unit will allow you to understand how such a light works.
- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Molecular_and_Atomic_Spectroscopy_(Wenzel)/6%3A_Atomic_Spectroscopy/6.4%3A_Other_Considerations
- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Molecular_and_Atomic_Spectroscopy_(Wenzel)/4%3A_Infrared_Spectroscopy/4.1%3A_Introduction_to_Infrared_SpectroscopyInfrared radiation is the proper energy to excite vibrations in molecules. The IR spectrum consists of near (4,000-12,800 cm-1), mid (200-4,000 cm-1) and far (10-200 cm-1) regions. The mid-IR region...Infrared radiation is the proper energy to excite vibrations in molecules. The IR spectrum consists of near (4,000-12,800 cm-1), mid (200-4,000 cm-1) and far (10-200 cm-1) regions. The mid-IR region is most commonly used for analysis purposes. Vibrational excitations correspond to changes in the internuclear distances within molecules. You have likely recorded infrared spectra in your organic chemistry course.
- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Molecular_and_Atomic_Spectroscopy_(Wenzel)/4%3A_Infrared_SpectroscopyDetermine the vibrations for a triatomic molecule and identify whether they are infrared-active. Draw the design of a non-dispersive infrared spectrophotometer and describe how it functions. Describe ...Determine the vibrations for a triatomic molecule and identify whether they are infrared-active. Draw the design of a non-dispersive infrared spectrophotometer and describe how it functions. Describe the difference between time and frequency domain spectra. Explain how a Michelson Interferometer can be used to obtain a time domain spectrum. Explain the advantages of Fourier Transform infrared spectroscopy over conventional infrared spectroscopy.
- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Molecular_and_Atomic_Spectroscopy_(Wenzel)/6%3A_Atomic_Spectroscopy/6.3%3A_Instrument_Design_Features_of_Atomic_Absorption_Spectrophotometers/6.3C%3A_Spectral_InterferencesThe answer is to alternately send the output from the hollow cathode lamp and a continuum source (the common one used in AA instruments is a deuterium lamp) to the flame. Without going into the detail...The answer is to alternately send the output from the hollow cathode lamp and a continuum source (the common one used in AA instruments is a deuterium lamp) to the flame. Without going into the details of the Zeeman Effect, what is important to know is that exposing an atomic vapor to a strong magnetic field causes a slight splitting of the energy levels of the atom causing a series of closely spaced lines for each electronic transition.
- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Molecular_and_Atomic_Spectroscopy_(Wenzel)/6%3A_Atomic_Spectroscopy/6.1%3A_Introduction_to_Atomic_SpectroscopyIt is also important to recognize that the absorption or emission spectrum of a neutral atom will be different than that of its ions (e.g., Cr 0 , Cr 3 + , Cr 6 + all have different lines in their abs...It is also important to recognize that the absorption or emission spectrum of a neutral atom will be different than that of its ions (e.g., Cr 0 , Cr 3 + , Cr 6 + all have different lines in their absorption or emission spectra). Just like the selection of the best wavelength in molecular spectroscopic measurements, provided there are no interfering substances, the optimal wavelength in atomic spectroscopic measurements is the wavelength of maximum absorbance or emission intensity.
- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Molecular_and_Atomic_Spectroscopy_(Wenzel)/2%3A_Ultraviolet_Visible_Absorption_Spectroscopy/2.5%3A_ApplicationsThen standards must be analyzed in a strongly basic solution, such that all of the species is in the A – form, to generate a standard curve for A – . At intermediate pH values close to the pKa, both H...Then standards must be analyzed in a strongly basic solution, such that all of the species is in the A – form, to generate a standard curve for A – . At intermediate pH values close to the pKa, both HA and A – will be present and the two standard curves can be used to calculate the concentration of each species.
- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Molecular_and_Atomic_Spectroscopy_(Wenzel)/6%3A_Atomic_Spectroscopy/6.2%3A_Atomization_Sources/6.2D%3A_Inductively_Coupled_PlasmaThe plasma is kept from melting the walls of the quartz tube by an additional tangential flow of argon along the walls of the tube. For a set of samples with unknown concentrations of analyte, it may ...The plasma is kept from melting the walls of the quartz tube by an additional tangential flow of argon along the walls of the tube. For a set of samples with unknown concentrations of analyte, it may be desirable to test one or two after dilution to insure that the concentration decreases by a proportional factor and that the samples are not so high in concentration to be out in the self-absorption portion of the standard curve.
- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Molecular_and_Atomic_Spectroscopy_(Wenzel)/2%3A_Ultraviolet_Visible_Absorption_SpectroscopyDetermine the effect of conjugation on a UV/Vis absorption spectrum. Determine the effect of non-bonding electrons on a UV/Vis absorption spectrum. Determine the effect of solvent on the energy of \(n...Determine the effect of conjugation on a UV/Vis absorption spectrum. Determine the effect of non-bonding electrons on a UV/Vis absorption spectrum. Determine the effect of solvent on the energy of n−pi∗ and π−π∗ transitions. Evaluate the utility of UV/Vis spectroscopy as a qualitative and quantitative method. Describe a procedure by which UV/Vis spectroscopy can be used to determine the pKa of a weak acid.
