15.2. Properties of Acids and Bases in Aqueous Solutions: The Brønsted-Lowry Scheme
Click on the title of a resource to view it. To save screen space, only the first 3 resources are shown. You can display more resources by scrolling down and clicking on “View all xx results”.
For the textbook, chapter, and section you specified we found
Ammonia Fountains - Multiple System of multiple ammonia fountains are set up and run. A separatory funnel, four round-bottomed flasks, and some tubing form a closed system. One end of the tubing is immersed in an acetic acid solution that contains universal indicator. The glassware has been filled with ammonia gas. The stopcock of the funnel is closed.
A 25.0 mL aliquot of a 1.44M solution of ammonia (Kb = 1.8 x 10-5) is titrated with 1.50M HCl. Use the Indicator Table below to decide which of the indicators listed would most accurately signal the equivalence point for this titration.
Write the letter corresponding to your choice of indicator in the box.
Dynamic Reaction Figures: An Integrative Vehicle for Understanding Chemical ReactionsEmeric Schultz Describes the dynamic reaction figure, a flexible learning tool that can be used to balance chemical equations, predict the results of potential reactions, present the underlying mechanism of reactions, and solve quantitative problems in a number of areas. Schultz, Emeric. J. Chem. Educ.2008, 85, 386.
Acids / Bases |
Aqueous Solution Chemistry |
Mechanisms of Reactions |
Nonmajor Courses
A Simplified Model To Predict the Effect of Increasing Atmospheric CO2 on Carbonate Chemistry in the OceanBrian J. Bozlee, Maria Janebo, and Ginger Jahn The chemistry of dissolved inorganic carbon in seawater is reviewed and used to predict the potential effect of rising levels of carbon dioxide in the atmosphere. It is found that calcium carbonate may become unsaturated in cold surface seawater by the year 2100, resulting in the destruction of calcifying organisms such as coral. Bozlee, Brian J.; Janebo, Maria; Jahn, Ginger. J. Chem. Educ.2008, 85, 213.
Applications of Chemistry |
Aqueous Solution Chemistry |
Atmospheric Chemistry |
Equilibrium |
Green Chemistry |
Water / Water Chemistry
Let Us Give Lewis Acid–Base Theory the Priority It DeservesAlan A. Shaffer The Lewis concept is simple yet powerful in its scope, and can be used to help beginning students understand reaction mechanisms more fully. However, traditional approaches to acid-base reactions at the introductory level ignores Lewis acid-base theory completely, focusing instead on proton transfer described by the Br?nsted-Lowry concept. Shaffer, Alan A. J. Chem. Educ.2006, 83, 1746.
ChemPaths 104 W Apr 6John W. Moore Today in Chem 104:
* Lecture: Bronsted Acids and Bases
* Reading:
Kotz: Ch. 17, Sec. 3-5
Moore: Ch. 16, Sec. 3-5
* Homework #9 due by 11:55 PM F Apr 8
* Quiz in second discussion section this week
* Lab this week is #10, Chemical Equilibrium and Thermodynamics
Brønsted-Lowry Acids / Bases
Introduction of Aquatic Chemistry in General Chemistry Curriculum;Spreadsheet Calculation ApproachesChulsung Kim Fundamental aquatic chemistry concepts may be introduced in general chemistry classes by computing ionization fractions and buffer intensity of aqueous phase carbonate systems. This Excel spreadsheet may used to build graphic presentations of a titration curve, distribution diagram, and buffer intensity as a function of pH. Accompanying activities are designed to enhance the concepts of acid-base equilibrium through exploring the relationship between pKa/pKb, pH of the solution, ionization fractions, and buffer intensity, and to exercise students graphing skills.
Acids / Bases |
Aqueous Solution Chemistry |
pH |
Titration / Volumetric Analysis |
Water / Water Chemistry |
Equilibrium
Molecular Models of EDTA and Other Chelating AgentsWilliam F. Coleman Deirdre Bell-Oudry presents a variation on an old theme in her paper on using an indirect EDTA titration for sulfate analysis (1). EDTA and (often loosely) related species are this month's Featured Molecules.EDTA is a hexaprotic acid (H6Y2+) having the pKa values given in the featured paper (1). Figure 1 shows a distribution diagram for the EDTA system (2). At the pH of normal waters, the predominant species have one or both of the nitrogen atoms protonated.Complexation, however, requires that both nitrogens be deprotonated and it is generally assumed that the form that complexes with metal ions is Y4−. Structures of several forms of EDTA are included in the molecule collection (Figure 2). These structures are quite flexible having many conformations that are readily accessible at room temperature.An introduction to EDTA chemistry leads to broader questions of metal ion chelation or sequestration. Related chelating agents included in the molecule collection are EGTA, DCTA, NTA, BAPTA, and DTPA. Molecular dynamics and Hartree-Fock calculations on BAPTA (Figure 2) confirm that many conformations, ranging from those with the phenyl rings parallel to one another, to more elongated forms, are essentially isoenergetic in room temperature aqueous solution (3).Also included in the molecule collection are several crown ethers, an isophore (nonactin), and a cryptand. These not only provide students with a glimpse of the types of molecules being employed for metal ion sequestration but open a wide range of topics of current research in a variety of areas of inorganic, industrial, environmental, and biological chemistry.
