(a) Describe the difference between the following and list any particular advantages possessed by one over the other. (i) Hydrogen and deuterium discharge lamps as sources for ultraviolet radiations. (ii) Filters and Monochromators as wavelength selectors. (iii) Photovoltaic cells and phototubes as detectors for electromagnetic radiations.

(a) Describe the difference between the following and list any particular advantages possessed by one over the other. (i) Hydrogen and deuterium discharge lamps as sources for ultraviolet radiations. (ii) Filters and Monochromators as wavelength selectors. (iii) Photovoltaic cells and phototubes as detectors for electromagnetic radiations.

Principles of Instrumental Analysis

7th Edition

ISBN:9781305577213

Author:Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Publisher:Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Chapter7: Components Of Optical Instruments

Section: Chapter Questions

Problem 7.20QAP

See similar textbooks

Similar questions

(i) The detection of Mn by graphite furnace atomic absorption spectrometry (GFAAS) is sensitive to the presence of aluminium ions Al3+ which may form refractory compounds such as MnAl2O4. Comment on the possible impact of this compound on the measurements and what action may be taken to minimize this. (ii) Write a brief note on the best practice for the preparation of a calibration curve. (iii) Atomic absorption spectroscopy (AAS) is a powerful technique for the analysis of trace amounts of metals. Describe the two common atomic absorption methods used in the lab with reference to their comparative strengths and weaknesses.
(5) A sample of sodium phosphate is dissolved in water to give 100.00 mL of solution (Solution A). Then this solution is diluted 5 times to give the final solution (Solution B). Solution B is Known to contain 3.920 x 1022 number of PO43- ions, which has an absorption peak at 460 nm and absorbance value of 0.355 in a 1.000 cm cuvette. (i) Calculate the molar absorptivity of Solution B. (ii) What mass of sodium phosphate (MM 163.94 g/mol) dissolved in Solution A.
(a) Draw a block diagram of an atomic absorption spectrometer (AAS). Briefly describe the function of each components. (b) What is the process of atomization in atomic absorption spectrometer? Describe the steps of the process in the correct sequence. (c) State TWO interferences that are encountered in atomic absorption spectrometer. Suggest ONE solution to overcome the problem. (d.) What is the main difference, in terms of instrumentation, between atomic absorption spectrometer and atomic emission spectroscopy?
Atomic Spectroscopy (a) In terms of spectral shape, how are atomic spectra different from molecular spectra? What is the source of this difference? (b) Describe the decision-making process for picking a line for atomic emission analysis of a given analyte. (c) For quality assurance, spike recovery is not sufficient to establish confidence in an analytical procedure. Explain this statement. What should be done instead to demonstrate satisfactory performance of an instrumental method (including elemental analysis). (d) Find a literature example of atomic spectroscopy used for elemental analysis. State the operating conditions with sufficient detail to reproduce the analysis; Please answer very soon will give rating surely All questions complete Answer needed Please help me
The transmittance of a solution measured at 590 nm in a 1.5-cm cuvette was 76.2%. (a) What is the corresponding absorbance?(b) If the concentration is 0.0802 M, what is the absorptivity of this species at this wavelength? (c) If the absorptivity is 10,000 L mol-1 cm-1, what is the concentration?
If you are measuring manganese (Mn) absorption using AAS, which hollow cathode lamp would you select as your source and why?
b) Describe the principles of operation of graphite furnace Atomic Absorption Spectroscopy (GFAAS) and how can be used in forensic science. In you answer; (i) Explain the principle of Atomic Absorption Spectroscopy. (ii) Describe the principle components of the apparatus, particularly the light source and furnace (iii) Describe the three steps in atomising a liquid sample. (iv) Explain what is the role of matrix modifiers?
A molecular exclusion column has a diameter of 7.8 mm and a length of 30 cm. The solid portion of the particles occupies 20% of the volume, the pores occupy 40%, and the volume between particles occupies 40%. (a) At what volume would totally excluded molecules be expected to emerge? (b) At what volume would the smallest molecules be expected? (c) A mixture of polymers of various molecular masses is eluted between 23 and 27 mL. What does this imply about the retention mechanism for these solutes on the column?
(a) Describe step-by-step procedure how you would use atomic absorption to measure copper in urine?
(4) Electrons are no longer ejected from a sample of metal whenever it is illuminated by light with wavelength greater than 344nm. (a) Based on the table below, what is the most likely metal being illuminated? (b) If the sample is illuminated by light with wavelength 48.3nm, what is the stopping potential? (c) In the event this sample of metal were replaced by a metal with a smaller work function, but still illuminated with light with 48.3nm, would the kinetic energy of the ejected electrons increase or decrease? (d) What is the threshold frequency for cesium? Atom W (eV) Cesium 2.1 Calcium 2.9 Uranium 3.6 Cadmium 4.07 Lead 4.14 Niobium 4.3 Iron 4.5 Copper Cobalt 4.7 5 Gold 5.11 Platinum 6.35
Match each statement with one or more of the following: flame AA, flame photometry, atomic fluorescence, ICP, graphite furnace AA, and spark emission. (a) The technique that uses a partially ionized stream of argon gas called a plasma - (b) The technique in which a light source is used to excite atoms, the emission from which is then measured - (c) The three techniques that require light to be directed at the atomized ions - (d) The technique that utilizes a solid sample - (e) The four techniques that measure some form of light emission by excited atoms present in an atomizer - (f) The absorption technique in which the atoms are in the path of the light for a relatively short time - (g) The technique in which the emitting source may reach a temperature of 6000 K -
Answer the following :(i) What is the role of cryolite in the metallurgy of aluminium?(ii) Difference between roasting and calcination.(iii) What is meant by the term ‘chromatography’?