Volume 6, Issue 2

Using Balloons to Model Pi-Conjugated Systems and to Teach Frontier Molecular Orbital Theory
Original Research
Large-scale molecular orbital balloon models have been designed and developed for implementation in the general, organic, or physical chemistry classroom. The purposes of the models are to help students visualize and understand concepts of pi-bonding, conjugation, aromaticity, and cycloaddition reactions or symmetry-controlled reactions. Second-semester organic chemistry students have welcomed the models with positive responses, claiming that the 3D models bring 2D textbook and lecture images to life. The balloon models may be constructed and presented by the instructor during a formal lecture, or they may be constructed by students during problem-solving workshops. Short video tutorials have been created to demonstrate the construction of these inexpensive classroom manipulatives.
World Journal of Chemical Education. 2018, 6(2), 102-106. DOI: 10.12691/wjce-6-2-5
Pub. Date: April 16, 2018
18354 Views3428 Downloads3 Likes
Lone Pair Electron Discriminate Hybridization with Aromatic and Anti Aromatic behavior of Heterocyclic Compounds - Innovative Mnemonics
Original Research
In this approach, formulae based mnemonics by counting lone pair of electrons (localized or delocalized) have been highlighted by innovative and time economic way to enhance interest of students’ who belong to paranoia zone of chemistry for the prediction of Hybridization state of hetero atom and Aromatic, Anti aromatic, non aromatic behavior of different heterocyclic compounds. Here, I have tried to hub three (03) time economic mnemonics by including three (03) formulae for the prediction of hybridization of hetero atom, aromatic and anti aromatic behavior of heterocyclic compounds. This article encourages students to solve multiple choice type questions (MCQs) on ‘Aromaticity of Heterocyclic compounds’ at different competitive examinations in a time economic ground.
World Journal of Chemical Education. 2018, 6(2), 95-101. DOI: 10.12691/wjce-6-2-4
Pub. Date: April 04, 2018
8819 Views2638 Downloads1 Likes
Reactions of Precious and Inactive Metals with Acids
Original Research
In chemistry, the redox reactions play an important role. While studying chemistry at the universities, much attention is paid to the problems of redox processes. One of the most important issues is the interaction of metals with solutions of strong acids. To qualitatively evaluate the possibility of dissolving a metal in strong acids, one can use the electrochemical series of metals. Metals, which are on the left side from hydrogen in electrochemical series, react with strong acids and release hydrogen. Sulfuric acid and nitric acid, depending on their concentration in the solution, react with metals, releasing a whole spectrum of gaseous products. Solution of many questions of redox reactions are addressed by memorizing responses or reaction algorithms. However, a person cannot remember everything, ones does not need. In order to help students to understand and write oxidation-reduction equations and avoid learning by heart, the authors suggest calculating the electromotive force (EMF) of redox reactions and then predicting their thermodynamic probability under standard and real conditions. In the article reactions of inactive and precious metals (Cu, Au and Pt) with strong acids using standard and stationary potentials of metals, which allow to calculate EMF and predict a “thermodynamically favourable” reaction without performing an experiment, are explained.
World Journal of Chemical Education. 2018, 6(2), 91-94. DOI: 10.12691/wjce-6-2-3
Pub. Date: March 29, 2018
7489 Views2230 Downloads2 Likes
Teaching of Chemistry Applied. Development of a Laboratory-scale Fire Started
Original Research
The present laboratory work based in the preparation of fire started is proposed as an alternative in the teaching of chemistry for students of high school, with the purpose of articulate and integrate the abilities of students from the knowledge acquired. In this sense, is proposed the progression of learning, so that students develop from a specific concept towards the understanding of a phenomenon through a concrete and accessible teaching practice that assure that interaction. This practice allowed consolidating and expanding the teaching-learning process. Based on the interest in the topic propounded, the students were able to internalize the knowledge, reaching a satisfactory theoretical-practical relationship.
World Journal of Chemical Education. 2018, 6(2), 87-90. DOI: 10.12691/wjce-6-2-2
Pub. Date: March 12, 2018
9147 Views2089 Downloads
Laboratory Activities to Introduce Carbohydrates Qualitative Analysis to College Students
Original Research
This paper presents practical applications of a laboratory inquiry for systematic chemistry learning of carbohydrates. In the laboratory inquiry, students are requested to perform qualitative tests for monosaccharides, disaccharides, and polysaccharides. In addition to that, students are instructed to distinguish specific sugars from non-specific ones. The chemical knowledge and concepts of organic chemistry are actively used to reinforce the previous learning. Such practical activities promote students' readiness for their future career as lab technicians. Our approach is also to link all written laboratory activities with infographics or illustrations to facilitate well understanding of all practical laboratory steps.
World Journal of Chemical Education. 2018, 6(2), 82-86. DOI: 10.12691/wjce-6-2-1
Pub. Date: February 05, 2018
29611 Views4014 Downloads20 Likes