Stephen Lower of Simon Fraser University presents this site on a visual approach to acid-base problems. Lower says that although he still finds it important to teach students to solve acid-base problems algebraically, more work should be done using graphics. Here are some of the reasons he gives against the algebraic method: "1) It can be an awful lot of work. Have you ever noticed that many of the acid-base systems most commonly encountered (phosphate, citrate, salts such as ammonium acetate, amino acids, EDTA) are rarely treated in standard textbooks? Treating these analytically requires setting up a series of mass- and charge-balance expressions which must be solved simultaneously. 2) Most algebraic treatments are approximations anyway. 3) Equilibrium constants are not really. 4) All you get is a number: Algebraic approaches contribute almost nothing to the larger view of how an acid-base system behaves as the pH is changed." The graphical method provides an overall picture of the acid-base system. At the site, graphically illustrated (.gif) tutorials focus on acetic acid plotting and titration, pH of HAc and NaAc solutions, oxalic acid as a driprotic system, ammonium formate as a "weak-weak" salt, Phosphate, the carbonate system, and glycine as a zwitterion. A brief list of links is also provided.
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