TIGER

Other Resources: 21 results
The Nobel Prize and Aqua Regia  Robert Hetue
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Aqueous Solution Chemistry |
Precipitation / Solubility
Molecular Models of EDTA and Other Chelating Agents  William 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.
Aqueous Solution Chemistry
Hydration of Ions  Ed Vitz, John W. Moore
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Aqueous Solution Chemistry
Conjugate Acid-Base Pairs and pH  Ed Vitz, John W. Moore
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Aqueous Solution Chemistry
Ammonia (GCMP)  David M. Whisnant
Ammonia fountain: this is a resource in the collection "General Chemistry Multimedia Problems". In an ammonia fountain, a flask is filled with ammonia gas. A tube from the flask extends into a pan of water that contains phenolphthalein. When a rubber bulb full of water is squeezed, the water squirts into the flask. Water from the pan then is pushed into the flask and the indicator changes color. General Chemistry Multimedia Problems ask students questions about experiments they see presented using videos and images. The questions asked apply concepts from different parts of an introductory course, encouraging students to decompartmentalize the material.
Acids / Bases |
Aqueous Solution Chemistry
Ionic Equilibria in Aqueous Solutions in Foods  Sofia Erazo
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Equilibrium |
Nutrition |
Aqueous Solution Chemistry
Buffer Solutions  Ed Vitz, John W. Moore
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Acids / Bases |
Aqueous Solution Chemistry
Solubility and Molecular Structure  Ed Vitz, John W. Moore
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Precipitation / Solubility
Solubility and Molecular Structure in the Environment  Sarah Yue
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Precipitation / Solubility
The Common-Ion Effect  Ed Vitz, John W. Moore
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Precipitation / Solubility
The Solubilities of Salts of Weak Acids  Ed Vitz, John W. Moore
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Precipitation / Solubility
Hydrogen and Hydroxide Ions  Ed Vitz, John W. Moore
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Aqueous Solution Chemistry |
Water / Water Chemistry
Saturated and Supersaturated Solutions  Ed Vitz, John W. Moore
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Solutions / Solvents |
Precipitation / Solubility
Miscibility  Ed Vitz, John W. Moore
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Precipitation / Solubility |
Liquids
Ksp and calcium fortification  Sofia Erazo
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Precipitation / Solubility |
Nutrition
Calcium tartrate and treatment of wine waste-waters  Sofia Erazo
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Precipitation / Solubility |
Equilibrium
Solubility of calcium salts in foods  Sofia Erazo
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Precipitation / Solubility |
Nutrition
Low solubility salts in dairy products - Calcium phosphate and lactate  Sofia Erazo
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Precipitation / Solubility |
Nutrition
The Solubility Product  Ed Vitz, John W. Moore
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Precipitation / Solubility |
Equilibrium
Introduction of Aquatic Chemistry in General Chemistry Curriculum;Spreadsheet Calculation Approaches  Chulsung 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
Computer Simulations of Salt Solubility  Victor M. S. Gil, João C. M. Paiva
Computer Simulations of Salt Solubility provides an animated, visual interpretation of the different solubilities of related salts based on simple entropy changes associated with dissolution: configurational disorder and thermal disorder. This animation can also help improve students conceptual understanding of chemical equilibrium before any quantitative interpretation of equilibrium constants is attempted.
Computational Chemistry |
Solutions / Solvents |
Thermodynamics |
Equilibrium |
Precipitation / Solubility