World Journal of Chemical Education

The aim of this experience was to utilize the Inquiry Based Science Education, (IBSE) in order to offer the students a better understanding of the light-matter interaction. We have followed the phase separation process in mixtures of an organic monomer and nematic liquid crystals. The systems form liquid crystal droplets in a liquid crystal-saturated monomer matrix and in some cases the emulsions are stable over several months. Homogeneous droplet size distributions are obtained for faster cooling rates. We report the droplet size distribution and the behavior of optical rotation angle of solutions as liquid crystal percentage function. This work is an essential part of an apprenticeship developed during the “Professione Formatore in Didattica delle Scienze” Master, which takes place at the University of Calabria, with the authors taking part in it as trainees and that is gonna end in the month of October 2015.

World Journal of Chemical Education. 2015, 3(3), 78-81. DOI: 10.12691/wjce-3-3-5
Pub. Date: July 24, 2015

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On Balancing Acidic and Basic Reduction/Oxidation Reactions with a Calculator

by Matthew S. Fox

Commentary

Balancing chemical equations is a fundamental skill every chemist—from novice to professional—must have. In this report we present a calculator-based, linear algebraic method that balances even the most rigorous acidic and basic conditioned redox equations in an expeditious manner.

World Journal of Chemical Education. 2015, 3(3), 74-77. DOI: 10.12691/wjce-3-3-4
Pub. Date: June 15, 2015

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Quantitative Analysis of Alcoholic Drinks. Use of Calibration Curve Method to Determine the Alcoholic Degree of Samples of Paesanella, a Distillate of the Family of Grappa

by Checchetti Andrea

Original Research

Within the framework of laboratory activities relating to the teaching programof a fifth-year class of a technical school in Italy, we have determined, by the means of a spectrophotometer UV/vis, the alcoholic degree of a series of samples of Paesanella, a distillate of the family of grappa. In this experiment of quantitative analysis the students prepared anaqueous solution of ethanol to draw, by means of measurements of absorbance, the calibration line. The students found, making use of EXCEL, the linear equation with which to calculate the alcoholic degree of the samples of Paesanella.

World Journal of Chemical Education. 2015, 3(3), 70-73. DOI: 10.12691/wjce-3-3-3
Pub. Date: June 03, 2015

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Qualitative Measurement of pH and Mathematical Methods for the Determination of the Equivalence Point in Volumetric Analysis

by Andrea Checchetti and Jessica Lanzo

Original Research

In this article is presented a gradual path on the pH making use of the laboratory. The idea arises from the consideration that the laboratory does not have to be the place of the ritual repetition of standardized procedures, often carried out with materials and instruments prepared, but a method of approach to phenomena and situations that promote the active participation of students. We move from a qualitative measure of the pH of acidic solutions, basic and neutral, to quantitative measure of the equivalent point of an acid-base titration. The methodology used by the teachers is based on learning by doing: few notions of theory to learn the fundamental concepts and many laboratory activities that help the students to produce reports on their activity. The qualitative measurement of pH, using as an indicator the red onion of Tropea (Italy), was carried out in a lower secondary school, while the volumetric analysis has been at the center of lab activity addressed to fourth class of a technical institute. In particular, the attention has been focused on acid-base titrations and how to determine the equivalence point. In both school levels, the primary objective was the acquisition of the fundamental principles and practical skills relating to the methods of analysis. All activities have been selected and organized in order to constitute a valid and mutual integration with the theory, not only as a moment of experimental verification of what the students have learned in theory, but also, where possible, as a basic tool to derive laws, principles theoretical models starting from the experience.

World Journal of Chemical Education. 2015, 3(3), 64-69. DOI: 10.12691/wjce-3-3-2
Pub. Date: June 02, 2015

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Thermal Denaturation of Proteins and Chemical Equilibrium

by Laura Moroni, Cristina Gellini and Pier Remigio Salvi

Original Research

The thermal denaturation of proteins is considered as a process by means of which chemical equilibrium can be introduced to undergraduate students of Chemistry related curricula. In this approach chemical potential μ, Gibbs energy G, degree of advancement ξ and Le Châtelier principle are integrated with chemical equilibrium. With reference to α-Chymotrypsinogen A as a test case, the process is discussed in terms of a simplified two-state model. The activity is addressed to physical chemistry students in combination with computer-aided work mainly involving storage/manipulation of large data sets and plot preparation.

World Journal of Chemical Education. 2015, 3(3), 59-63. DOI: 10.12691/wjce-3-3-1
Pub. Date: May 17, 2015

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