Basic Analytical Chemistry: Acid-Base Concepts and the pH Scale

February 2010

Abstract
Acids and bases are chemical compounds always present in our daily life. They are important raw materials in manufacturing industries and are necessary for the control of various industrial processes. They participate actively in living organisms’ metabolism and, if improperly disposable they can alter the environmental conditions necessary to the human well-being. Acids have sour [...]


Basic Analytical Chemistry: Applications of the Fundamentals of Qualitative Analysis

November 2009

Abstract
The Chemical and physical phenomena and the principles applied in qualitative analysis to identify ions in aqueous solution are the same ones used in quantitative analysis of different samples and are still used in many official reference methods, including instrumental methods or procedures. This shows the importance of knowledge of the fundamentals of qualitative analysis, [...]


Basic Analytical Chemistry: Ionic Equilibrium in Aqueous Solution

September 2009

Abstract
Obeying the fundamental law of nature that says, “a physical or chemical system always tends to cause an irreversible change from some state of initial non-equilibrium to a final equilibrium”, chemical reactions can be defined as processes in which different substances interact with each other, with a rearrangement of atoms occurring that completely changes the [...]


Basic Analytical Chemistry: The role of Analytical Chemistry in the Formation of Classical Chemist

September 2009

Abstract
The content of Inorganic Qualitative Analytical Chemistry usually used by Brazilian Higher Education Institutions (HEIs) covers the theory of chemical equilibrium in aqueous solution and, in the laboratory, the separation and identification of cations and anions in solution or solid samples, using classical methods. As there are still opinions both fory and against the maintenance [...]


Basic Analytical Chemistry: A Historical Overview of Classical Qualitative Analysis

Abstract
History shows that nothing is totally new and therefore the old should not be discarded, but known so that new knowledge can be constructed. Thus, when interviewed by Rudy M. Baum, Henry Taube, Nobel Prize in Chemistry in 1983, said that the disappearance of qualitative analysis from the curriculum of American universities was a mistake, [...]


Didactic Experiments Using Voltammetric Measurements

Author: João Carlos de Andrade; Audrey de Arruda Falcão; Elaine Castilho Guedes
April 2007

Abstract
Some analytical techniques, such as voltammetry, are relatively little used in undergraduate experimental disciplines in chemistry (and related sciences), although addressed in theoretical ones. Since, in contrast to what one thinks, voltammetric measurements are still often used in routine analysis, some of the most direct techniques will be highlighted in this text, with suggestions to [...]


Determination of the Molar Mass of a Metal

Author: Janaína César; João Carlos de Andrade
April 2006

Abstract
Besides conceptual and quantitative aspects, studies in chemistry should involve experiments with a demanding high level of care and attention in the use of experimental techniques. Considering these aspects, the determination of the molar mass of a metal, through the volume of gas released by its reaction with an acid, is an ideal experiment to [...]


Supercritical Fluid Extraction

Author: Glaucia M. F. Pinto; Jefferson F. Pinto; Protimu Ltda; Isabel C. S. F. Jardim
April 2006

Abstract
This work presents a discussion about the characteristics of supercritical fluid extraction, its operational conditions, a comparison with other extraction techniques and analytical applications of this technique. The text shows that a supercritical fluid can be obtained with different substances if they are above their critical point, the critical temperature and critical pressure, which can [...]


Quantitative Analysis by Chromatography

Author: Antônio Luiz Pires Valente; Cássio Ricardo Fares Riedo; Fabio Augusto
October 2003

Abstract
This is a support text to the Quantitative Analysis by Chromatography multimedia application available in Applications and Programs. As its purpose is to provide the same material in printed form to the reader, this text is more detailed than that presented in the application, although with a smaller number of figures. It is also an [...]


Voltametry: Concepts and Techiniques

Author: Luiz Manoel Aleixo
March 2003

Abstract
This text will introduce the main voltammetric methods of analysis, from its basic aspects to applications in trace analysis. The techniques to be presented are continuous current (polarographic; DC, direct current), sampled direct current (sampled DC), normal pulse (NP, normal pulse), differential pulse and square wave voltammetry. The use of voltammetry in trace analysis is [...]






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