Example 1 Nicotinic Acid Is a Monoprotic Acid

Total Page:16

File Type:pdf, Size:1020Kb

Example 1 Nicotinic Acid Is a Monoprotic Acid Weak acids and bases Example 1 Nicotinic acid is a monoprotic acid. A solution that is 0.012 M in nicotinic acid has a pH of 3.39. What is the acid ionization constant (Ka)? What is the degree of ionization of nicotinic acid in this solution? Solution When we say the solution is 0.012 M, this refers to how the solution is prepared. The solution is made up by adding 0.012 mol of substance to enough water to give a liter of solution. Once the solution is prepared, some molecules ionize, so the actual concentration is somewhat less than 0.012 M. - + We start with 0.012 M of acid (HNic) before ionization, i.e. [Nic ]=0 before ionization. The H3O concentration at the start is that from the self-ionization of water. It is usually much smaller than that obtained from the acid (unless the solution is extremely dilute or Ka is quite small), so you can write + + – [H3O ] = ~ 0 (meaning approximately zero). If x mol HNic ionizes, x mol each of H3O and Nic is formed, leaving (0.012 - x) mol HNic in solution. You can summarize the situation in the table: + – Concentration (M) HNic(aq) + H2O(l) <==> H3O (aq) + Nic (aq) Starting 0.012 ~0 0 Change -x +x +x Equilibrium 0.012 - x x x The equilibrium-constant equation is + – [H3O ][Nic ] Ka = [HNic] When you substitute the expressions for the equilibrium concentrations, you get x2 Ka = (0.012 - x) The value of x equals the numerical value of the molar hydronium-ion concentration, and can be obtained from the pH of the solution. + –pH –3.39 –4 x = [H3O ] = 10 = 10 = 4.1 x 10 = 0.00041 You can substitute this value of x into the above equation. x2 (0.00041)2 –5 Ka = = = 1.45 x 10 (0.012 - x) 0.012-0.00041 To obtain the degree of ionization, note that x mol out of 0.012 mol of nicotinic acid ionizes. Hence, x 0.00041 Degree of ionization = = = 0.034 0.012 0.012 The percent ionization is obtained by multiplying this by 100, which gives 3.4%. Example 2 What are the concentrations of nicotinic acid, hydrogen ion, and nicotinate ion in a solution of 0.10 M nicotinic acid (HC6H4NO2), at 25°C? What is the pH of the solution? What is the degree of ionization of nicotinic acid? The acid-ionization constant is 1.4 x 10-5. Solution As above, at the start (before ionization), the concentration of nicotinic acid, HNic, is 0.10 M and that of - + its conjugate base, Nic , is 0. The concentration of H3O is essentially zero (~ 0), assuming that the contribution from the self-ionization of water can be neglected. In 1 L of solution, the nicotinic acid + - ionizes to give x mol H3O and x mol Nic , leaving (0.10 - x) mol of nicotinic acid. These data are summarized in the following table: + - Concentration (M) HNic(aq) + H2O(l) <==> H3O (aq) + Nic (aq) Starting 0.10 ~0 0 Change -x +x +x Equilibrium 0.10 - x x x + – The equilibrium concentrations of HNic, H3O , and Nic are (0.10 - x), x, and x, respectively. Now substitute these concentrations and the value of Ka into the equilibrium-constant equation for acid ionization: + - 2 [H3O ][Nic ] x -5 = Ka or = 1.4 x 10 [HNic] (0.10 - x) This is actually a quadratic equation, but it can be simplified so that the value of x is easily found. Because the acid-ionization constant is small ( Ka <<< cHNic, the value of x is small. Assume that x is much smaller than 0.10, so that 0.10 - x ~ 0.10. The equilibrium-constant equation becomes x2 = 1.4 x 10-5 0.10 x 1.4 10 -5 ××= 0.10 Hence, x = 0.0012 . Now you can substitute the value of x into the last line of the table to find the concentrations of species. The concentrations of nicotinic acid, hydronium ion, and nicotinate ion are 0.10 M, 0.0012 M, and 0.0012 + M, respectively. The pH of the solution is pH = –log [H3O ] = –log (0.0012) = 2.92 The degree of ionization equals the amount per liter of nicotinic acid that ionizes (x = 0.0012) divided by the total amount per liter of nicotinic acid initially present (0.10). Thus, the degree of ionization is 0.0012/0.10 = 0.012 = 1.2%. Example 3 –6 What is the pH of a 0.300 M solution of morphine? Kb = 1.62 x 10 These are the important equations: + Mor + H2O <==> MorH + OH¯ + –6 Kb = ( [MorH ] [OH¯] ) / [Mor] = 1.62 x 10 Mor refers to the morphine molecule and MorH+ refers to the molecule after accepting a proton. It is completely unimportant what its formula is. We need the [OH¯]. So we have: [OH¯] = x and [MorH+] = x This is because of the one-to-on molar ratio between [OH¯] and [MorH+] that is created as Mor molecules react with the water. Remember, the [Mor] started at 0.300 M and went down as Mor molecules reacted. In fact, due to the one-to-one ratio, it went down by 'x' amount and wound up at an ending value of 0.300 - x. x2 = 1.62 x 10-6 0.30-x Kb <<< cHNic, the value of x is small. So that 0.30 - x ~ 0.30. The equilibrium-constant equation becomes x2 = 1.62 x 10-6 0.30 0.30 10 1.62 x 1.62 10 -6 ××= 0.30 x = 6.97 x 10–4 M We take the pOH to get 3.157. Converting to pH (remember pH + pOH = 14), we get a pH = 10.843 Exercises 1, A 0.025 M solution of lactic acid has a pH of 2.75. What is the acid ionization constant (Ka)? What is the degree of ionization? (1.36×10–4, 7.11%) 2, What are the concentrations of acetic acid, hydrogen ion, and acetate ion in a solution of 0.10 M acetic acid? What is the pH of the solution? What is the degree of ionization? The acid-ionization constant is 1.86 x 10-5. (0.0986 M, 1.36×10–3 M, 1.36×10–3 M, 1.36%) 3, Calculate the acid ionization constant for propionic acid (C2H5–COOH). The pH of a 0.012 M aqueous solution is 3.40. (1.37×10–5) –4 4, A solution of 0.020 M nitrous acid (HNO2) has a pH of 2.53. What is the value of Ka? (5.1×10 ) 5, What is the pH of a 0.20 M solution of formic acid? What is the degree of ionization of formic acid in –4 this solution? Ka = 1.7×10 . (2.234, 2,92%) 6, Calculate the concentration of hydrogen ion and barbiturate ion in a 0.20 M solution of barbituric acid. –5 –3 –3 The value of Ka is 9.8×10 . (4.43×10 M, 4.43×10 M) 7, A 0.15 M aqueous solution of ethanolamine has a pH of 11.34. What is Kb for ethanolamine? − 2 – –2.66 []OH (pOH = 2.66, [OH ] = 10 , K = =3.24 × 10−5 ) b c−[] OH − 8, What is the concentration of hydroxide ion in a 0.50 M aqeous solution of methylamine? What is the –4 –2 pH? Kb = 4.4×10 . (1.48×10 M, 12.17) –5 9, A solution of 0.25 M trimethylamine has a pH of 11.63. What is the value of Kb? (7.41×10 ) 10, What is the concentration of hydroxide ion in a 0.15 M aqeous solution of hydroxylamine? What is –8 –5 the pH? Kb = 1.1×10 . (4.06×10 M, 9.61) .
Recommended publications
  • Excitation Temperature, Degree of Ionization of Added Iron Species, and Electron Density in an Exploding Thin Film Plasma
    SpectmchimiccrACIO. Vol. MB. No. II. Pp.10814096. 1981. 0584-8547/81/111081-16SIZ.CNI/O Printedin Great Britain. PerpmonPress Ltd. Excitation temperature, degree of ionization of added iron species, and electron density in an exploding thin film plasma S. Y. SUH* and R. D. SACKS Department of Chemistry, University of Michigan, Ann Arbor, Ml 48109, U.S.A. (Received 7 April 1981) Abstract-Time and spatially resolved spectra of a cylindrically symmetric exploding thin film plasma were obtained with a rotating mirror camera and astigmatic imaging. These spectra were deconvoluted to obtain relative spectral emissivity profiles for nine Fe(H) and two Fe(I) lines. The effective (electronic) excitation temperature at various positions in the plasma and at various times during the first current halfcycle was computed from the Fe(H) emissivity values using the Boltzmann graphical method. The Fe(II)/Fe(I) emissivity ratios together with the temperature were used to determine the degree of ionization of Fe. Finally, the electron density was estimated from the Saha equilibrium. Electronic excitation temperatures range from lO,OOO-15,OOOKnear the electrode surface at peak discharge current to 700&10.000K at 6-10 mm above the electrode surface at the first current zero. Corresponding electron densities range from 10’7-10u cm-’ at peak current to 10’~-10’6cm-3 near zero current. Error propagation and criteria for thermodynamic equilibrium are discussed. 1. IN-~R~DU~~ION THE HIGH-TEMPERATURE plasmas produced by the rapid electrical vaporization of Ag thin films recently have been used as atomization cells and excitation sources for the direct determination of selected elements in micro-size powder samples [ 11.
    [Show full text]
  • Ionization Balance in EBIT and Tokamak Plasmas N
    Ionization balance in EBIT and tokamak plasmas N. J. Peacock, R. Barnsley, M. G. O’Mullane, M. R. Tarbutt, D. Crosby et al. Citation: Rev. Sci. Instrum. 72, 1250 (2001); doi: 10.1063/1.1324755 View online: http://dx.doi.org/10.1063/1.1324755 View Table of Contents: http://rsi.aip.org/resource/1/RSINAK/v72/i1 Published by the American Institute of Physics. Related Articles Bragg x-ray survey spectrometer for ITER Rev. Sci. Instrum. 83, 10E126 (2012) Novel energy resolving x-ray pinhole camera on Alcator C-Mod Rev. Sci. Instrum. 83, 10E526 (2012) Measurement of electron temperature of imploded capsules at the National Ignition Facility Rev. Sci. Instrum. 83, 10E121 (2012) South pole bang-time diagnostic on the National Ignition Facility (invited) Rev. Sci. Instrum. 83, 10E119 (2012) Temperature diagnostics of ECR plasma by measurement of electron bremsstrahlung Rev. Sci. Instrum. 83, 073111 (2012) Additional information on Rev. Sci. Instrum. Journal Homepage: http://rsi.aip.org Journal Information: http://rsi.aip.org/about/about_the_journal Top downloads: http://rsi.aip.org/features/most_downloaded Information for Authors: http://rsi.aip.org/authors Downloaded 08 Aug 2012 to 194.81.223.66. Redistribution subject to AIP license or copyright; see http://rsi.aip.org/about/rights_and_permissions REVIEW OF SCIENTIFIC INSTRUMENTS VOLUME 72, NUMBER 1 JANUARY 2001 Ionization balance in EBIT and tokamak plasmas N. J. Peacock,a) R. Barnsley,b) and M. G. O’Mullane Euratom/UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB, United Kingdom M. R. Tarbutt, D. Crosby, and J. D. Silver The Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom J.
    [Show full text]
  • How the Saha Ionization Equation Was Discovered
    How the Saha Ionization Equation Was Discovered Arnab Rai Choudhuri Department of Physics, Indian Institute of Science, Bangalore – 560012 Introduction Most youngsters aspiring for a career in physics research would be learning the basic research tools under the guidance of a supervisor at the age of 26. It was at this tender age of 26 that Meghnad Saha, who was working at Calcutta University far away from the world’s major centres of physics research and who never had a formal training from any research supervisor, formulated the celebrated Saha ionization equation and revolutionized astrophysics by applying it to solve some long-standing astrophysical problems. The Saha ionization equation is a standard topic in statistical mechanics and is covered in many well-known textbooks of thermodynamics and statistical mechanics [1–3]. Professional physicists are expected to be familiar with it and to know how it can be derived from the fundamental principles of statistical mechanics. But most professional physicists probably would not know the exact nature of Saha’s contributions in the field. Was he the first person who derived and arrived at this equation? It may come as a surprise to many to know that Saha did not derive the equation named after him! He was not even the first person to write down this equation! The equation now called the Saha ionization equation appeared in at least two papers (by J. Eggert [4] and by F.A. Lindemann [5]) published before the first paper by Saha on this subject. The story of how the theory of thermal ionization came into being is full of many dramatic twists and turns.
    [Show full text]
  • 1 Introduction
    i i Karl-Heinz Spatschek: High Temperature Plasmas — Chap. spatscheck0415c01 — 2011/9/1 — page 1 — le-tex i i 1 1 Introduction A plasma is a many body system consisting of a huge number of interacting (charged and neutral) particles. More precisely, one defines a plasma as a quasineu- tral gas of charged and neutral particles which exhibits collective behavior. In many cases, one considers quasineutral gases consisting of charged particles, namely electrons and positively charged ions of one species. Plasmas may contain neutral atoms. In this case, the plasma is called partially or incompletely ionized. Other- wise the plasma is said to be completely or fully ionized. The term plasma is not limited to the most common electron–ion case. One may have electron–positron plasmas, quark-gluon plasmas, and so on. Semiconductors contain plasma con- sisting of electrons and holes. Most of the matter in the universe occurs in the plasma state. It is often said that 99% of the matter in the universe is in the plasma state. However, this estimate may not be very accurate. Remember the discussion on dark matter. Nevertheless, the plasma state is certainly dominating the universe. Modern plasma physics emerged in 1950s, when the idea of thermonuclear re- actor was introduced. Fortunately, modern plasma physics completely dissociated from weapons development. The progression of modern plasma physics can be retraced from many monographs, for example, [1–15]. In simple terms, plasmas can be characterized by two parameters, namely, charged particle density n and temperature T. The density varies over roughly 28 6 34 3 orders of magnitude, for example, from 10 to 10 m .
    [Show full text]
  • Lecture 8: Statistical Equilibria, Saha Equation
    Statistical Equilibria: Saha Equation We are now going to consider the statistics of equilibrium. Specifically, suppose we let a system stand still for an extremely long time, so that all processes can come into balance. We then measure the fraction of particles that are in each of several states (e.g., if we have a pure hydrogen gas, we might want to know the ionization fraction). How can we compute this fraction? We’ll take a look at this in several different ways. We will then step back and ask ourselves when these equilibrium formulae do not apply. This is important! To paraphrase Clint Eastwood, “An equation’s got to know its limitations”. In virtually all astronomical problems we deal with approximations, so we always need a sense of when those approximations fail. This serves a double purpose: it keeps us from making errors, but it also keeps us from applying too complex an approach to a simple problem. Let’s start out with a simple case. We consider a column of isothermal gas (temperature T ) in a constant gravitational acceleration g. Each molecule has mass m. If we can treat this like an ideal gas, Ask class: how do we figure out how the pressure vary with height h? An ideal gas has pressure P = nkT , where n is the number density. In equilibrium the pressure gradient balances the weight of the gas, so dP/dh = −ρg. Using ρ = nm = P m/kT and the constancy of T , we have dP/dh = −(mg/kT )P , so P = P0 exp(−mgh/kT ), where P0 is defined as the pressure at h = 0.
    [Show full text]
  • Lecture Notes in Physics Introduction to Plasma Physics
    Lecture Notes in Physics Introduction to Plasma Physics Michael Gedalin ii Contents 1 Basic definitions and parameters 1 1.1 What is plasma . 1 1.2 Debye shielding . 2 1.3 Plasma parameter . 4 1.4 Plasma oscillations . 5 1.5 ∗Ionization degree∗ ............................ 5 1.6 Summary . 6 1.7 Problems . 7 2 Plasma description 9 2.1 Hierarchy of descriptions . 9 2.2 Fluid description . 10 2.3 Continuity equation . 10 2.4 Motion (Euler) equation . 11 2.5 State equation . 12 2.6 MHD . 12 2.7 Order-of-magnitude estimates . 14 2.8 Summary . 14 2.9 Problems . 15 3 MHD equilibria and waves 17 3.1 Magnetic field diffusion and dragging . 17 3.2 Equilibrium conditions . 18 3.3 MHD waves . 19 3.4 Alfven and magnetosonic modes . 22 3.5 Wave energy . 23 3.6 Summary . 24 3.7 Problems . 24 iii CONTENTS 4 MHD discontinuities 27 4.1 Stationary structures . 27 4.2 Discontinuities . 28 4.3 Shocks . 29 4.4 Why shocks ? . 31 4.5 Problems . 32 5 Two-fluid description 33 5.1 Basic equations . 33 5.2 Reduction to MHD . 34 5.3 Generalized Ohm’s law . 35 5.4 Problems . 36 6 Waves in dispersive media 37 6.1 Maxwell equations for waves . 37 6.2 Wave amplitude, velocity etc. 38 6.3 Wave energy . 40 6.4 Problems . 44 7 Waves in two-fluid hydrodynamics 47 7.1 Dispersion relation . 47 7.2 Unmagnetized plasma . 49 7.3 Parallel propagation . 49 7.4 Perpendicular propagation . 50 7.5 General properties of the dispersion relation .
    [Show full text]
  • 193 9Ap J. the PHYSICAL STATE of INTERSTELLAR HYDROGEN Co
    CDco CMLO OC CO THE PHYSICAL STATE OF INTERSTELLAR J. HYDROGEN 9Ap BENGT STRÖMGREN 193 ABSTRACT The discovery, by Struve and Elvey, of extended areas in the Milky Way in which the Balmer lines are observed in emission suggests that hydrogen exists, in the ionized state, in large regions of space. The problem of the ionization and excitation of hydro- gen is first considered in a general way. An attempt is then made to arrive at a picture of the actual physical state of interstellar hydrogen. It is found that the Balmer-line emission should be limited to certain rather sharply bounded regions in space surround- ing O-type stars or clusters of O-type stars. Such regions may have diameters of about zoo parsecs, which is in general agreement with the observations. Certain aspects of the problem of the ionization of other elements and of the problem of the relative abundance of the elements in interstellar space are briefly discussed. The interstellar density of hydrogen is of the order of A = 3 cm-3. The extent of the emission regions at right angles to the galactic plane is discussed and is found to be small. I The recent discovery, by Struve and Elvey,1 of extended regions in the Milky Way showing hydrogen-hne emission has opened up new and highly important possibilities for the study of the properties of interstellar matter. From the observed strength of Z7a in the emission regions, Struve2 has calculated the density of interstellar hydrogen. Also, he has analyzed the problem of the ionization of interstellar calcium and sodium, taking account of the presence of ionized hydrogen.
    [Show full text]
  • Lecture Note 1
    Lecture Note 1 1.1 Plasma 99% of the matter in the universe is in the plasma state. Solid -> liquid -> Gas -> Plasma (The fourth state of matter) Recall: Concept of Temperature A gas in thermal equilibrium has particles of all velocities, and the most probable distribution of these velocities is known as the Maxwellian distribution. The average kinetic energy Eav equals 1/2kT per degree of freedom. k is Boltzmann’s constant. Since T and Eav are so closed related, it is customary in plasma physics to give temperatures in units of energy. To avoid confusion on the number of dimensions involved, it is not Eav , but the energy corresponding to kT that is used to denote the temperature. For kT = 1 eV = 1.6 x 10-19 J, we have 1.6× 10−19 T ==11,600 1.38× 10−23 Thus the conversion factor is 1eV = 11,600 K A plasma is a gas in which an important fraction of the atoms in ionized, so that the electrons and ions are separately free. When does this ionization occur? When the temperature is hot enough. Saha Equation: Which tells us the amount of ionization to be expected in a gas in thermal equilibrium: 3/2 ni 21 T ≈×2.4 10 exp( −UkTi / ) nnni 3 Here ni and nn are, respectively, the number density (number per m ) of ionized atoms and of neutral atoms, T is the gas temperature in K, k is Boltzmann’s constant, and Ui is the ionization energy of the gas—that is, the number of ergs required to remove the outmost electron from an atom.
    [Show full text]
  • Statistical Equilibria: Saha Equation Initial Questions: What Sets the Temperature of the Warm Interstellar Medium? What Determi
    Statistical Equilibria: Saha Equation Initial questions: What sets the temperature of the warm interstellar medium? What determines the epoch from which we see the CMB? We are now going to consider the statistics of equilibrium. Specifically, suppose we let a system stand still for an extremely long time, so that all processes can come into balance. We then measure the fraction of particles that are in each of several states (e.g., if we have a pure hydrogen gas, we might want to know the ionization fraction). How can we compute this fraction? We’ll take a look at this in several different ways. We will then step back and ask ourselves when these equilibrium formulae do not apply. This is important! To paraphrase Clint Eastwood, “An equation’s got to know its limitations”. In virtually all astronomical problems we deal with approximations, so we always need a sense of when those approximations fail. This serves a double purpose: it keeps us from making errors, but it also keeps us from applying too complex an approach to a simple problem. Let’s start out with a simple case. We consider a column of isothermal gas (temperature T ) in a constant gravitational acceleration g. Each molecule has mass m. If we can treat this like an ideal gas, Ask class: how do we figure out how the pressure varies with height h? An ideal gas has pressure P = nkT , where n is the number density. In equilibrium the pressure gradient balances the weight of the gas, so dP/dh = −ρg. Using ρ = nm = Pm/kT and the constancy of T , we have dP/dh = −(mg/kT )P , so P = P0 exp(−mgh/kT ), where P0 is defined as the pressure at h = 0.
    [Show full text]
  • Charge and Energy Interactions Between Nanoparticles and Low Pressure Plasmas
    Charge and Energy Interactions between Nanoparticles and Low Pressure Plasmas A DISSERTATION SUBMITTED TO THE FACULTY OF THE GRADUATE SCHOOL OF THE UNIVERSITY OF MINNESOTA BY Federico Galli IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY Prof. Uwe R. Kortshagen, Adviser May 2010 © Federico Galli May 2010 Acknowledgments I would like to thank my adviser, Professor Uwe Kortshagen, for his guidance and mentoring during the years of my graduate career. To my colleagues and friends in the HTPL group and at the University of Minnesota: thank you for five years of intellectual and personal enrichment. To all the friends and people that I had the opportunity to meet here in Minnesota: you made me feel like at home. Last but first in my heart: thank you family, for everything. i Abstract In this work, the interactions between low-pressure plasmas and nanoparticles are studied with numerical models aimed at understanding the phenomena that affect the nanoparticles charge, charge distribution, heating, and crystallization dinamycs. At the same time other phenomena that affect the plasma properties resulting from the presence of nanoparticles are also studied: they include the power-coupling to the plasmas, the ion energy distribution and the electron energy distribution. An analytical model predicting the nano-particle charge and temperature distribu- tions in a low pressure plasma is developed. The model includes the effect of collisions between ions and neutrals in proximity of the particles. In agreement with experi- mental evidence for pressures of a few Torr a charge distribution that is less negative than the prediction from the collisionless orbital motion limited theory is obtained.
    [Show full text]
  • Diagnostic Studies of Ion Beam Formation in Inductively Coupled Plasma Mass Spectrometry with the Collision Reaction Interface Jeneé L
    Iowa State University Capstones, Theses and Graduate Theses and Dissertations Dissertations 2015 Diagnostic studies of ion beam formation in inductively coupled plasma mass spectrometry with the collision reaction interface Jeneé L. Jacobs Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/etd Part of the Analytical Chemistry Commons Recommended Citation Jacobs, Jeneé L., "Diagnostic studies of ion beam formation in inductively coupled plasma mass spectrometry with the collision reaction interface" (2015). Graduate Theses and Dissertations. 14814. https://lib.dr.iastate.edu/etd/14814 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. i Diagnostic studies of ion beam formation in inductively coupled plasma mass spectrometry with the collision reaction interface by Jeneé L. Jacobs A dissertation submitted to the graduate faculty in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Major: Analytical Chemistry Program of Study Committee: Robert S. Houk, Major Professor Young-Jin Lee Emily Smith Patricia Thiel Javier Vela Iowa State University Ames, Iowa 2015 Copyright © Jeneé L. Jacobs, 2015. All right reserved. ii TABLE OF CONTENTS ABSTRACT vi CHAPTER 1. GENERAL INTRODUCTION 1 Inductively Coupled Plasma Mass Spectrometry 1 ICP 1 Ion Extraction 3 Polyatomic Ion Interferences 4 Polyatomic Ion Mitigation Techniques 5 Characteristics of Collision Technology 7 Dissertation Organization 8 References 9 Figures 14 CHAPTER 2.
    [Show full text]
  • Degree of Ionization of a Plasma in Equilibrium *
    Degree of Ionization of a Plasma in Equilibrium * G. ECKER and W. KRÖLL Institut für Theoretische Physik der Universität Bochum ** (Z. Naturforschg. 21 a, 2023—2027 [1966] ; received 20 August 1966) Previous investigations derived the SAHA equation for a plasma in equilibrium applying the free-bound concept valid for an isolated electron-ion pair. In our investigation of the "adapted free-bound model" (I) we have shown that due to the free-bound interaction the demarcation be- tween free and bound states is shifted by A%= —e2/r0 . We study the influence of this shift of the ionization limit on the effective ionization energy in SAHA'S equation. At the same time we account by interpolation for the contributions of the quasi-free highly correlated particles. The lowering of the free-bound limit causes an increase of the effective lowering of the ionization energy in SAHA'S equation beyond the well-known e2/ö-term resulting from the free-free interaction. This ad- ditional term itself is of the order 0{e2/D) and therewith much stronger than the correction found from higher order correlations of the free particles. On the other hand it is much smaller than the lowering of the free-bound limit. SAHA'S equation is used to describe the degree of tive, but frequently intuitive on the basis of simple ionization of a system in equilibrium. In writing models. down this equation it is common practice to treat Different results for this effective lowering of the the free and bound states of the electrons and ions ionization energy have been obtained so far: as two different particle kinds, which do not interact The term Ax% = e2/D (D — DEBYE length, e — ele- with each other.
    [Show full text]