Acid-Base Reactions/ the Ph Concept
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Wastewater Technology Fact Sheet: Ammonia Stripping
United States Office of Water EPA 832-F-00-019 Environmental Protection Washington, D.C. September 2000 Agency Wastewater Technology Fact Sheet Ammonia Stripping DESCRIPTION Ammonia stripping is a simple desorption process used to lower the ammonia content of a wastewater stream. Some wastewaters contain large amounts of ammonia and/or nitrogen-containing compounds that may readily form ammonia. It is often easier and less expensive to remove nitrogen from wastewater in the form of ammonia than to convert it to nitrate-nitrogen before removing it (Culp et al., 1978). Ammonia (a weak base) reacts with water (a weak acid) to form ammonium hydroxide. In ammonia stripping, lime or caustic is added to the wastewater until the pH reaches 10.8 to 11.5 standard units which converts ammonium hydroxide ions to ammonia gas according to the following reaction(s): + - NH4 + OH 6 H2O + NH38 Source: Culp, et. al, 1978. Figure 1 illustrates two variations of ammonia FIGURE 1 TWO TYPES OF STRIPPING stripping towers, cross-flow and countercurrent. In TOWERS a cross-flow tower, the solvent gas (air) enters along the entire depth of fill and flows through the packing, as the alkaline wastewater flows it may be more economical to use alternate downward. A countercurrent tower draws air ammonia removal techniques, such as steam through openings at the bottom, as wastewater is stripping or biological methods. Air stripping may pumped to the top of a packed tower. Free also be used to remove many hydrophobic organic ammonia (NH3) is stripped from falling water molecules (Nutrient Control, 1983). droplets into the air stream, then discharged to the atmosphere. -
Introduction to Co2 Chemistry in Sea Water
INTRODUCTION TO CO2 CHEMISTRY IN SEA WATER Andrew G. Dickson Scripps Institution of Oceanography, UC San Diego Mauna Loa Observatory, Hawaii Monthly Average Carbon Dioxide Concentration Data from Scripps CO Program Last updated August 2016 2 ? 410 400 390 380 370 2008; ~385 ppm 360 350 Concentration (ppm) 2 340 CO 330 1974; ~330 ppm 320 310 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 Year EFFECT OF ADDING CO2 TO SEA WATER 2− − CO2 + CO3 +H2O ! 2HCO3 O C O CO2 1. Dissolves in the ocean increase in decreases increases dissolved CO2 carbonate bicarbonate − HCO3 H O O also hydrogen ion concentration increases C H H 2. Reacts with water O O + H2O to form bicarbonate ion i.e., pH = –lg [H ] decreases H+ and hydrogen ion − HCO3 and saturation state of calcium carbonate decreases H+ 2− O O CO + 2− 3 3. Nearly all of that hydrogen [Ca ][CO ] C C H saturation Ω = 3 O O ion reacts with carbonate O O state K ion to form more bicarbonate sp (a measure of how “easy” it is to form a shell) M u l t i p l e o b s e r v e d indicators of a changing global carbon cycle: (a) atmospheric concentrations of carbon dioxide (CO2) from Mauna Loa (19°32´N, 155°34´W – red) and South Pole (89°59´S, 24°48´W – black) since 1958; (b) partial pressure of dissolved CO2 at the ocean surface (blue curves) and in situ pH (green curves), a measure of the acidity of ocean water. -
Major Ions, Carbonate System, Alkalinity, Ph (Kalff Chapters 13 and 14) A. Major Ions 1. Common Ions There Are 7 Common Ions I
Major Ions, Carbonate System, Alkalinity, pH (Kalff Chapters 13 and 14) A. Major ions 1. Common Ions There are 7 common ions in freshwater: (e.g. Table 13-3, p207) +2 +2 +1 +1 cations: Ca , Mg , Na , K -1 -2 -1 anions: Cl , SO4 , HCO3 +1 -1 In some surface waters, other ionic species are sometimes important (e.g. NH4 , F , organic acids, etc.), but in most cases the 7 ions listed above are the only ions present in significant concentration. In addition to the common ions, OH-1 and H+1 are important species because of the dissociation of water itself. In freshwater, the total concentration of ions and the relative abundance of each are highly variable, reflecting the influence of precipitation (rain), weathering and evaporation. In contrast to freshwater, the world ocean is very uniform (Table 13-6, p214). The total concentration of ions varies only slightly, depending on local advection of freshwater from major rivers and regions of surplus rainfall or evaporation. For “standard” seawater, with “chlorinity” = 19.000 parts per thousand, the following concentrations are observed for the common ions. (Similar ratios are available for nearly the entire periodic table, although at lower concentrations.) These fixed ratios in the sea are the result of the “constancy of composition” of seawater. Ion parts per thousand (g/kg) - - - Cl 18.980 (the definition of "clorinity" includes Br , I , etc.) + Na 10.556 -2 SO4 2.649 +2 Mg 1.272 +2 Ca 0.400 + K 0.380 - HCO3 0.140 Br- 0.065 2. Sources of ions in freshwater a. -
The Strongest Acid Christopher A
Chemistry in New Zealand October 2011 The Strongest Acid Christopher A. Reed Department of Chemistry, University of California, Riverside, California 92521, USA Article (e-mail: [email protected]) About the Author Chris Reed was born a kiwi to English parents in Auckland in 1947. He attended Dilworth School from 1956 to 1964 where his interest in chemistry was un- doubtedly stimulated by being entrusted with a key to the high school chemical stockroom. Nighttime experiments with white phosphorus led to the Headmaster administering six of the best. He obtained his BSc (1967), MSc (1st Class Hons., 1968) and PhD (1971) from The University of Auckland, doing thesis research on iridium organotransition metal chemistry with Professor Warren R. Roper FRS. This was followed by two years of postdoctoral study at Stanford Univer- sity with Professor James P. Collman working on picket fence porphyrin models for haemoglobin. In 1973 he joined the faculty of the University of Southern California, becoming Professor in 1979. After 25 years at USC, he moved to his present position of Distinguished Professor of Chemistry at UC-Riverside to build the Centre for s and p Block Chemistry. His present research interests focus on weakly coordinating anions, weakly coordinated ligands, acids, si- lylium ion chemistry, cationic catalysis and reactive cations across the periodic table. His earlier work included extensive studies in metalloporphyrin chemistry, models for dioxygen-binding copper proteins, spin-spin coupling phenomena including paramagnetic metal to ligand radical coupling, a Magnetochemi- cal alternative to the Spectrochemical Series, fullerene redox chemistry, fullerene-porphyrin supramolecular chemistry and metal-organic framework solids (MOFs). -
A Guide to Acids, Acid Strength, and Concentration
A GUIDE TO ACIDS, ACID STRENGTH, AND CONCENTRATION What’s the difference between acid strength and concentration? And how does pH fit in with these? This graphic explains the basics. CH COOH HCl H2SO4 HNO3 H3PO4 HF 3 H2CO3 HYDROCHLORIC ACID SULFURIC ACID NITRIC ACID PHOSPHORIC ACID HYDROFLUORIC ACID ETHANOIC ACID CARBONIC ACID pKa = –7 pKa = –2 pKa = –2 pKa = 2.12 pKa = 3.45 pKa = 4.76 pKa = 6.37 STRONGER ACIDS WEAKER ACIDS STRONG ACIDS VS. WEAK ACIDS ACIDS, Ka AND pKa CONCENTRATION AND pH + – The H+ ion is transferred to a + A decrease of one on the pH scale represents + [H+] [A–] pH = –log10[H ] a tenfold increase in H+ concentration. HA H + A water molecule, forming H3O Ka = pKa = –log10[Ka] – [HA] – – + + A + + A– + A + A H + H H H H A H + H H H A Ka pK H – + – H a A H A A – + A– A + H A– H A– VERY STRONG ACID >0.1 <1 A– + H A + + + – H H A H A H H H + A – + – H A– A H A A– –3 FAIRLY STRONG ACID 10 –0.1 1–3 – – + A A + H – – + – H + H A A H A A A H H + A A– + H A– H H WEAK ACID 10–5–10–3 3–5 STRONG ACID WEAK ACID VERY WEAK ACID 10–15–10–5 5–15 CONCENTRATED ACID DILUTE ACID + – H Hydrogen ions A Negative ions H A Acid molecules EXTREMELY WEAK ACID <10–15 >15 H+ Hydrogen ions A– Negative ions Acids react with water when they are added to it, The acid dissociation constant, Ka, is a measure of the Concentration is distinct from strength. -
Properties of Acids and Bases
GREEN CHEMISTRY LABORATORY MANUAL Lab 22 Properties of Acids and Bases TN Standard 4.2: The student will investigate the characteristics of acids and bases. Have you ever brushed your teeth and then drank a glass of orange juice? hat do you taste when you brush your teeth and drink orange juice afterwards. Yuck! It leaves a really bad taste in your mouth, but why? Orange juice and toothpaste by themselves taste good. But the terrible taste W results because an acid/base reaction is going on in your mouth. Orange juice is a weak acid and the toothpaste is a weak base. When they are placed together they neutralize each other and produce a product that is unpleasant to taste. How do you determine what is an acid and what is a base? In this lab we will discover how to distinguish between acids and bases. Introduction Two very important classes of compounds are acids and bases. But what exactly makes them different? There are differences in definition, physical differences, and reaction differences. According to the Arrhenius definition, acids ionize in water to + produce a hydronium ion (H3O ), and bases dissociate in water to produce hydroxide ion (OH -). Physical differences can be detected by the senses, including taste and touch. Acids have a sour or tart taste and can produce a stinging sensation to broken skin. For example, if you have ever tasted a lemon, it can often result in a sour face. Bases have a bitter taste and a slippery feel. Soap and many cleaning products are bases. -
Introduction to Ionic Mechanisms Part I: Fundamentals of Bronsted-Lowry Acid-Base Chemistry
INTRODUCTION TO IONIC MECHANISMS PART I: FUNDAMENTALS OF BRONSTED-LOWRY ACID-BASE CHEMISTRY HYDROGEN ATOMS AND PROTONS IN ORGANIC MOLECULES - A hydrogen atom that has lost its only electron is sometimes referred to as a proton. That is because once the electron is lost, all that remains is the nucleus, which in the case of hydrogen consists of only one proton. The large majority of organic reactions, or transformations, involve breaking old bonds and forming new ones. If a covalent bond is broken heterolytically, the products are ions. In the following example, the bond between carbon and oxygen in the t-butyl alcohol molecule breaks to yield a carbocation and hydroxide ion. H3C CH3 H3C OH H3C + OH CH3 H3C A tertiary Hydroxide carbocation ion The full-headed curved arrow is being used to indicate the movement of an electron pair. In this case, the two electrons that make up the carbon-oxygen bond move towards the oxygen. The bond breaks, leaving the carbon with a positive charge, and the oxygen with a negative charge. In the absence of other factors, it is the difference in electronegativity between the two atoms that drives the direction of electron movement. When pushing arrows, remember that electrons move towards electronegative atoms, or towards areas of electron deficiency (positive, or partial positive charges). The electron pair moves towards the oxygen because it is the more electronegative of the two atoms. If we examine the outcome of heterolytic bond cleavage between oxygen and hydrogen, we see that, once again, oxygen takes the two electrons because it is the more electronegative atom. -
Ocean Storage
277 6 Ocean storage Coordinating Lead Authors Ken Caldeira (United States), Makoto Akai (Japan) Lead Authors Peter Brewer (United States), Baixin Chen (China), Peter Haugan (Norway), Toru Iwama (Japan), Paul Johnston (United Kingdom), Haroon Kheshgi (United States), Qingquan Li (China), Takashi Ohsumi (Japan), Hans Pörtner (Germany), Chris Sabine (United States), Yoshihisa Shirayama (Japan), Jolyon Thomson (United Kingdom) Contributing Authors Jim Barry (United States), Lara Hansen (United States) Review Editors Brad De Young (Canada), Fortunat Joos (Switzerland) 278 IPCC Special Report on Carbon dioxide Capture and Storage Contents EXECUTIVE SUMMARY 279 6.7 Environmental impacts, risks, and risk management 298 6.1 Introduction and background 279 6.7.1 Introduction to biological impacts and risk 298 6.1.1 Intentional storage of CO2 in the ocean 279 6.7.2 Physiological effects of CO2 301 6.1.2 Relevant background in physical and chemical 6.7.3 From physiological mechanisms to ecosystems 305 oceanography 281 6.7.4 Biological consequences for water column release scenarios 306 6.2 Approaches to release CO2 into the ocean 282 6.7.5 Biological consequences associated with CO2 6.2.1 Approaches to releasing CO2 that has been captured, lakes 307 compressed, and transported into the ocean 282 6.7.6 Contaminants in CO2 streams 307 6.2.2 CO2 storage by dissolution of carbonate minerals 290 6.7.7 Risk management 307 6.2.3 Other ocean storage approaches 291 6.7.8 Social aspects; public and stakeholder perception 307 6.3 Capacity and fractions retained -
Multidisciplinary Design Project Engineering Dictionary Version 0.0.2
Multidisciplinary Design Project Engineering Dictionary Version 0.0.2 February 15, 2006 . DRAFT Cambridge-MIT Institute Multidisciplinary Design Project This Dictionary/Glossary of Engineering terms has been compiled to compliment the work developed as part of the Multi-disciplinary Design Project (MDP), which is a programme to develop teaching material and kits to aid the running of mechtronics projects in Universities and Schools. The project is being carried out with support from the Cambridge-MIT Institute undergraduate teaching programe. For more information about the project please visit the MDP website at http://www-mdp.eng.cam.ac.uk or contact Dr. Peter Long Prof. Alex Slocum Cambridge University Engineering Department Massachusetts Institute of Technology Trumpington Street, 77 Massachusetts Ave. Cambridge. Cambridge MA 02139-4307 CB2 1PZ. USA e-mail: [email protected] e-mail: [email protected] tel: +44 (0) 1223 332779 tel: +1 617 253 0012 For information about the CMI initiative please see Cambridge-MIT Institute website :- http://www.cambridge-mit.org CMI CMI, University of Cambridge Massachusetts Institute of Technology 10 Miller’s Yard, 77 Massachusetts Ave. Mill Lane, Cambridge MA 02139-4307 Cambridge. CB2 1RQ. USA tel: +44 (0) 1223 327207 tel. +1 617 253 7732 fax: +44 (0) 1223 765891 fax. +1 617 258 8539 . DRAFT 2 CMI-MDP Programme 1 Introduction This dictionary/glossary has not been developed as a definative work but as a useful reference book for engi- neering students to search when looking for the meaning of a word/phrase. It has been compiled from a number of existing glossaries together with a number of local additions. -
Drugs and Acid Dissociation Constants Ionisation of Drug Molecules Most Drugs Ionise in Aqueous Solution.1 They Are Weak Acids Or Weak Bases
Drugs and acid dissociation constants Ionisation of drug molecules Most drugs ionise in aqueous solution.1 They are weak acids or weak bases. Those that are weak acids ionise in water to give acidic solutions while those that are weak bases ionise to give basic solutions. Drug molecules that are weak acids Drug molecules that are weak bases where, HA = acid (the drug molecule) where, B = base (the drug molecule) H2O = base H2O = acid A− = conjugate base (the drug anion) OH− = conjugate base (the drug anion) + + H3O = conjugate acid BH = conjugate acid Acid dissociation constant, Ka For a drug molecule that is a weak acid The equilibrium constant for this ionisation is given by the equation + − where [H3O ], [A ], [HA] and [H2O] are the concentrations at equilibrium. In a dilute solution the concentration of water is to all intents and purposes constant. So the equation is simplified to: where Ka is the acid dissociation constant for the weak acid + + Also, H3O is often written simply as H and the equation for Ka is usually written as: Values for Ka are extremely small and, therefore, pKa values are given (similar to the reason pH is used rather than [H+]. The relationship between pKa and pH is given by the Henderson–Hasselbalch equation: or This relationship is important when determining pKa values from pH measurements. Base dissociation constant, Kb For a drug molecule that is a weak base: 1 Ionisation of drug molecules. 1 Following the same logic as for deriving Ka, base dissociation constant, Kb, is given by: and Ionisation of water Water ionises very slightly. -
Guide to Best Practices for Ocean CO2 Measurements
Guide to Best Practices for Ocean C0 for to Best Practices Guide 2 probe Measurments to digital thermometer thermometer probe to e.m.f. measuring HCl/NaCl system titrant burette out to thermostat bath combination electrode In from thermostat bath mL Metrohm Dosimat STIR Guide to Best Practices for 2007 This Guide contains the most up-to-date information available on the Ocean CO2 Measurements chemistry of CO2 in sea water and the methodology of determining carbon system parameters, and is an attempt to serve as a clear and PICES SPECIAL PUBLICATION 3 unambiguous set of instructions to investigators who are setting up to SPECIAL PUBLICATION PICES IOCCP REPORT No. 8 analyze these parameters in sea water. North Pacific Marine Science Organization 3 PICES SP3_Cover.indd 1 12/13/07 4:16:07 PM Publisher Citation Instructions North Pacific Marine Science Organization Dickson, A.G., Sabine, C.L. and Christian, J.R. (Eds.) 2007. P.O. Box 6000 Guide to Best Practices for Ocean CO2 Measurements. Sidney, BC V8L 4B2 PICES Special Publication 3, 191 pp. Canada www.pices.int Graphic Design Cover and Tabs Caveat alkemi creative This report was developed under the guidance of the Victoria, BC, Canada PICES Science Board and its Section on Carbon and climate. The views expressed in this report are those of participating scientists under their responsibilities. ISSN: 1813-8519 ISBN: 1-897176-07-4 This book is printed on FSC certified paper. The cover contains 10% post-consumer recycled content. PICES SP3_Cover.indd 2 12/13/07 4:16:11 PM Guide to Best Practices for Ocean CO2 Measurements PICES SPECIAL PUBLICATION 3 IOCCP REPORT No. -
Characterization of the Acidity of Sio2-Zro2 Mixed Oxides
Characterization of the acidity of SiO2-ZrO2 mixed oxides Citation for published version (APA): Bosman, H. J. M. (1995). Characterization of the acidity of SiO2-ZrO2 mixed oxides. Technische Universiteit Eindhoven. https://doi.org/10.6100/IR436698 DOI: 10.6100/IR436698 Document status and date: Published: 01/01/1995 Document Version: Publisher’s PDF, also known as Version of Record (includes final page, issue and volume numbers) Please check the document version of this publication: • A submitted manuscript is the version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal.