Chem Refff

Topics: Chemistry, Laboratory equipment, Chemical reaction Pages: 17 (3762 words) Published: February 21, 2015
FUNDAMENTALS OF CHEMISTRY – Vol. I - Chemical Laboratory Techniques - Gelosa D. and Sliepcevich A.

CHEMICAL LABORATORY TECHNIQUES
Gelosa D. and Sliepcevich A.
Politecnico di Milano, Italy
Keywords: batch reactor, boiling point, boiling stones, bubble-plate columns, continuous reactor, cooling bath, crystallization, drying, electric hot plate, electric mantle, equipment, extraction, filtration, fractional distillation, glass joint, glassware, heating bath, laboratory, nonpolar solvents, packed columns, polar solvents, purification, separation, simple distillation, steam distillation, stirring, technique, tubular reactor, vacuum distillation, vacuum pump.

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Contents
1. Common Laboratory Apparatus
1.1. Glassware
1.2. Heating of the Reaction Mixture
1.2.1. Burners
1.2.2. Heating Baths
1.2.3. Electric Hot Plates and Electric Heating Mantles
1.3. Cooling of the Reaction Mixtures
1.4. Stirring
2. The Reaction
2.1. Batch Reactors
2.2. Continuous Stirred-Tank Reactors
2.3. Tubular Reactors
2.3.1. Pulse Reactors
3. Isolation and Purification Techniques
3.1. Filtration
3.2. Extraction
3.2.1. Liquid–Liquid Extraction
3.2.2. Liquid–Solid Extraction
3.3. Crystallization
3.4. Distillation
3.4.1. Theoretical Aspects
3.4.2. Simple Distillation
3.4.3. Fractional Distillation
3.4.4. Distillation under Reduced Pressure
3.4.5. Steam Distillation
Glossary
Bibliography
Biographical Sketches
Summary
Basic laboratory techniques in chemistry have an essential place in the training of a chemist. They provide a good background for experimental skills and for subsequent

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FUNDAMENTALS OF CHEMISTRY – Vol. I - Chemical Laboratory Techniques - Gelosa D. and Sliepcevich A.

independent research. In this chapter, first of all, we shall consider some of the standard pieces of glassware and equipment that you will use in the laboratory.

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By assembling suitable apparatus, you can carry out reactions from starting materials to pure products. Sometimes these operations require particular laboratory reactors that work in well-defined operation conditions. At the end of the reaction different techniques are needed in order to separate the products from the reaction mixture, and then the final compound will need to be purified by means of specific operations. The separation of reaction products is obtained by techniques such as extraction with solvents, crystallization, and distillation. These methods, which are almost standardized, are often able to purify organic compounds by separating the impurities. Chromatographic methods are very effective in separating more complex mixtures. Standard safety practices are an essential part of all laboratory operations. The chemicals employed in the laboratory can be flammable or irritating, and many possess known or as yet undetermined toxic characteristics. Accidents in the chemistry laboratory can be avoided if you enter the laboratory properly prepared for the experiment, if you use common sense in reacting to unexpected situations, and if you rigidly follow basic safety rules that are enforced to ensure your personal safety. 1. Common Laboratory Apparatus

The first section of this article provides an introduction to various pieces of equipment—glassware and nonglassware—that are used in the laboratory. 1.1. Glassware

Glass equipment can be divided into those with ground-glass joints and those without. New techniques of glassworking and the employment of glasses with a very low expansion have allowed the mass production of really interchangeable, standard-taper, ground-glass joints. Therefore standard-taper, ground-glass joint equipment is strongly recommended. In fact, apparatus for a range of experiments can be assembled quickly and easily from relatively few basic items and there is no need to utilize corks...

Bibliography: Brewster R., Vanderwerf C.A., and McEwen W.E. (1977). Unitized Experiments in Organic Chemistry.
Doyle M.P. and Mungall W.S. (1976). Experimental Organic Chemistry, 490 pp. New York: John Wiley
& Sons
Henkel K.D. (1992). Reactor types and their industrial applications. Ullmann’s Encyclopedia of Industrial
Chemistry
O’Connor R.F. (1971). Fundamentals of the Modern Chemistry Laboratory, 234 pp.. London: Scott,
Foresman and Co
Richardson J.A. and Rase H.F. (1978). Continuous stirred microreactors as a laboratory tool. Industrial
Engineering Chemical Products Research and Development 17(4): 287–296
Tarmy B.L. (1995). Reactor technology. Encyclopedia of Chemical Technology. Fourth Edition, Vol. 20,
(ed
Weekman V.W. (1974). Laboratory reactors and their limitations. AIChE (American Institute of Chemical
Engineering) Journal 20(5): 833–839
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