General chemistry experiments

From the data in Fig. 4.8b, estimate the shift factors required to displace the data at 0 = 0.5 (consider only this point) so that all runs superimpose on the experiment conducted at 128 C at 0 = 0.5. Either a ruler or proportional dividers can be used to measure displacements. Criticize or defend the following proposition Whether a buffered aqueous solution of H2O2 and 1. containing small amounts of S2O3 and starch, appears blue or colorless depends on both the time and the temperature. This standard general chemistry experiment could be used to demonstrate the equivalency of time and temperature. The pertinent reactions for the iodine clock are... 

R. H. Eastman, General Chemistry, Experiment and Theory, Holt, Rinehart and Winston, New York, 1970. 

Hiemenz, P. and E. Pfeiffer (1972) A general chemistry experiment for the blind. Journal of Chemical Education 49,263-265. 

Finally, the usual general chemistry experiment for the preparation of oxygen involves the decomposition of KCIO3 ... 

Tripp, T. B. Nadenu, J. L. Roadside Salt Pollution and the Absorption-Emission Spectra of Sodium—A General Chemistry Experiment, J. Chem. Educ. 1974, 51, 130. 

Engerer, S.C., Cook, A.G. (1999). The Blue Bottle Reaction as a general chemistry experiment on reaction mechanism. Journal of Chemical Education, 76, 1519-1520. 

The Primis LabBase is by Joseph Lagowski (the University of Texas at Austin). More than 40 general chemistry experiments are available in this database collection of... 

The terminal groups of a polymer chain are different in some way from the repeat units that characterize the rest of the molecule. If some technique of analytical chemistry can be applied to determine the number of these end groups in a polymer sample, then the average molecular weight of the polymer is readily evaluated. In essence, the concept is no different than the equivalent procedure applied to low molecular weight compounds. The latter is often included as an experiment in general chemistry laboratory classes. The following steps outline the experimental and computational essence of this procedure ... 

This is surprising in view of the fact that a great deal of effort was made to study transition metal complexes in chloroaluminate ionic liquids in the 1980s and early 1990s (see Section 6.1 for some examples). The investigations at this time generally started with electrochemical studies [41], but also included spectroscopic and complex chemistry experiments [42]. 

Stone, Dunn, and McCullough— Experiments in General Chemistry... 

MO (molecular orbital) theory (Appendix 5). Our experience has been (and continues to be) that although this approach is important to chemical bonding, most general chemistry students do not understand it but only memorize the principles discussed in the classroom. 

You ve probably already heard a lot about your general chemistry course. Many think it is more difficult than other courses. There may be some justification for that opinion. Besides having its very own specialized vocabulary, chemistry is a quantitative science, which means that you need mathematics as a tool to help you understand the concepts. As a result, you will probably receive a lot of advice from your instructor, teaching assistant, and fellow students about how to study chemistry. We hesitate to add our advice experience as teachers and parents has taught us that students do surprisingly well without it We would, however, like to acquaint you with some of the learning tools in this text. They are described in the pages that follow. 

During an experiment, a chemist may measure physical quantities such as mass, volume, and temperature. Usually the chemist seeks information that is related to the measured quantities but must be found by doing calculations. In later chapters we develop and use equations that relate measured physical quantities to important chemical properties. Calculations are an essential part of all of chemistry therefore, they play important roles in much of general chemistry. The physical property of density illustrates how to apply an equation to calculations. 

The Scholars, working with their mentors, did an outstanding job during their residencies, and many laboratory experiments and new lecture snapshots were developed. Lecture snapshots are short discussions of timely or fundamental polymer topics. They are designed to minimize the time necessary for faculty to familiarize themselves with the topic and to prepare their presentation on it In general, the lecture snapshots require only a few minutes of lecture time and setup and interface with topics that already are covered in general chemistry courses. The snapshot format is as follows ... 

In addition to the lecture snapshots, a variety of experiments suitable for general chemistry lab classes were developed ... 

The experiments were tested by student assistants at the University of Wisconsin—Stevens Point with good success. Most of the experiments do not require any special equipment beyond that found in a typical general chemistry lab. 

In a classic experiment that was conducted for decades in general chemistry laboratories, oxygen can be prepared by the decomposition of KC103 in the presence of Mn02. 

This experiment requires skill and careful technique in order to obtain accurate results. As with most surface chemistry experiments cleanliness is of paramount importance. High-energy liquids such as water easily pick up surface-active contaminants from the air in a laboratory and great care should be taken to reduce exposure. Contaminants generally do not adsorb at the surface of low-energy liquids such as hexane and hence are less of a problem. 

In recent years there has been renewed interest in renovating general chemistry courses in colleges and universities. Much of this interest has focused on the laboratory. Laboratory experience is an essential part of learning chemistry. It helps students comprehend concepts and develop skills to a degree that cannot be accomplished by... 

In some general chemistry laboratory courses the following experiment is done to evaluate Avogadro s number. A watch glass is filled to the brim with water, and then a solution of stearic acid in benzene is slowly deposited dropwise on the surface until such... 

A. K. Sawyer, Solubility and Ksp of Calcium Sulfate A General Chemistry Laboratory Experiment, J. Chem. Ed 1983,60, 416. 

A demonstration of potentiometry with a silver electrode (or a microscale experiment for general chemistry) is described by D. W. Brooks, D. Epp, and H. B. Brooks, Small-Scale Potentiometry and Silver One-Pot Reactions, ... 

Typical exposure to mercury in the General Chemistry laboratory occurs during (A) Boyle s Law experiments, (B) thermal decomposition of mercuric oxide, (C) displacement of mercury from its dissolved salts, and (D) cleaning up spills from broken thermometers. 

The inorganic material that probably poses the greatest risk to General Chemistry students is the liquid metal, mercury. One way to reduce the level of mercury vapor in the laboratory would be to have the instructor do some of the experiments as demonstrations. Any metallic mercury that must be kept in the laboratory should be stored in covered containers, so that there are no open pools, and mercury spills should be cleaned up immediately. 

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