Environmental examples

Using Environmental Examples to Teach About Acids. Acid-base reactions are usually presented to secondary students as examples of aqueous equilibrium (2). In their study of acids and bases, students are expected to master the characteristic properties and reactions. They are taught to test the acidity of solutions, identify familiar acids and label them as strong or weak. The ionic dissociation of water, the pH scale and some common reactions of acids are also included in high school chemistry. All of these topics may be illustrated with examples related to acid deposition (5). A lesson plan is presented in Table I. 

Support from Environmental Scientists. High school teachers need advice in selecting the most meaningful environmental examples, a list that may have to change every few years. Support from university and industrial chemists is also needed to encourage more school boards to approve modifying the present curriculum to incorporate global environmental issues. 

Acid, use of environmental examples for instruction, 468,469r Acid deposition... 

The solubility of substances such as carboxylic acids, which dissociate or form ions in solution, is also a function of pH, a common environmental example being pentachlo-rophenol. Data must thus be at a specified pH. Alternatively, the solubility of the parent (non-ionic) form may be given, and pKa or pKb given, to permit the ratio of ionic to nonionic forms to be calculated as... 

The various time series analytical methods were applied to the same environmental example - a series of nitrate concentrations in a storage reservoir. A comparison of the power of time series methods is, therefore, possible. 

The environmental example given leads to the observation that analytical chemistry, when accuracy is important, is not different from other fields of metrology. Namely ... 

APME. 2001. Environmental examples Material recycling. Association of Plastics Manufacturers in Europe, ivww.apme.org. 

Table 10.15. Chemical variables used in selected environmental examples...

Chemistry and chemical engineering subdivisions not coherent with environmental problems environmental aspects of chemistry and chemical engineering not always treated or sold well barriers to cross-disciplinary work need more use of environmental examples at undergraduate level greater need to align multidisciplinary programs and expectations of graduate students... 

In some cases, the small amount of a nonpolar gas that does dissolve is essential to a process. The most important environmental example is the solubility of O2 in water. At 25°C and 1 atm, the solubility of O2 is only 3.2 mL/100. mL of water, but aquatic animal life would die without this small amount. In other cases, the solubility of a gas may seem high because the gas is not only dissolving but also reacting with the solvent or another component. Oxygen seems much more soluble in blood than in water because O2 molecules are continually bonding with... 

Other common environmental examples of quantitative GC are in the determination of pesticides in water, dioxin levels in soil and air pollutants. It is routinely used to examine levels of volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). It is also a very important technique in the food industry, where it is used extensively for assay of fatty acids, flavours, sterols and residues such as insecticides, herbicides, preservatives, solvents and veterinary drugs. 

VII. Analysis of Organic Matter Analysis in Environmental Examples. 302... 

VII. ANALYSIS OF ORGANIC MATTER ANALYSIS IN ENVIRONMENTAL EXAMPLES... 

Calixarenes are conical-shaped macrocyclic oligomers whose inner cavity can accommodate several guest molecules and, therefore, can serve as a viable option to replace CDs in EKC separations. Environmental examples of the use of calixarene as EKC secondary phases include the separation of chlorinated phenols, benzenediols, and toluidines." Sulfonated calixarenes have also been used as chromophores in the indirect detection of aliphatic amines." ... 

In this section, some recent environmental examples are presented in order to view the actual applicability of each one of the ionization techniques. 

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