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 [...]


Catalysis by Coordination Compounds

Author: Regina Buffon
October 2006

Abstract
Until 1960, catalysts based on coordination compounds were little used and they were mainly employed on the laboratory scale. Since then, however, there has been a rapid emergence of new catalytic systems, mainly due to developments in Organometalic Chemistry, due in large part to the use of organometallic complexes (and / or coordination compounds) in [...]


The Concept of Thermodynamic Properties

Author: Adalberto B. M. S. Bassi
May 2006

Abstract
Initially the ideas of classical magnitude and classical body, continuous media, temporal and constitutive functions, density and rate will be shown, the latter being related to the rudimentary concepts of derivatives and functions. Then the concept of property is indicated, without the use of mathematical expressions, as well as the classification of properties into intensive, [...]


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 [...]


The Use of a Graph of Residuals in the Modeling of Chemical Data

Author: Aline Renée Coscione; Audrey de Arruda Falcão; João Carlos de Andrade
April 2006

Abstract
The method of response surface analysis is employed to optimize the catalytic response of the Mo (VI) in the oxidation reaction of iodide ions by hydrogen peroxide, using the fixed time method. The absorbances of the non-catalytic reaction and the catalytic action of Mo (VI), the delta, were modeled. This was done in detail to [...]






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