Volume 5, Issue 4

Introducing Organic Chemistry Students to the Extraction of Natural Products Found in Vegetal Species
Original Research
This work constitutes a new strategy for teaching-learning the chemistry of natural products, being the students active participants in the process. Results showed in this activity contributed not only to the understanding of the subject but also turned out to be an important pillar of motivation. An essential oil is any of a class of volatile oils that give plants their characteristic odor. Essential oils are also known as ethereal oil, volatile oil, aetherolea, or simply as the oil of the plant from which they are extracted, such as oil of clove. The oil is “essential” in the sense that it contains the “essence of” vegetal specie fragrance, the characteristic fragrance of the plant from which it is derived. These can be extracted from different parts of plants such as stems, leaves and flowers. In this work, two conventional methods (steam distillation and Soxhlet extraction) and one non-conventional method (microwave-assisted extraction), was developed under different conditions from clove. The yield of clove oil and yield of eugenol were obtained; and the concentration of eugenol present was assessed by gas chromatography. The main objective was that the experimental activity with the theoretical foundation will provide to the students of organic chemistry the ability to link concepts and develop skills in the laboratory.
World Journal of Chemical Education. 2017, 5(4), 142-147. DOI: 10.12691/wjce-5-4-5
Pub. Date: August 17, 2017
22330 Views5007 Downloads7 Likes
Avogadro Program for Chemistry Education: To What Extent can Molecular Visualization and Three-dimensional Simulations Enhance Meaningful Chemistry Learning?
Original Research
In developing this study, we hypothesized that the integration of computerized techniques and modeling tools into traditional face-to-face instruction can produce a better hybrid model of teaching, capable of motivating students and improving their attitude toward science in general, and toward chemistry in particular. We tested how molecular visualizations and three-dimensional simulations affect students’ conceptual understanding of chemistry and their attitudes toward learning chemistry. During the academic year 2016-2017, we incorporated Avogadro software into teaching and tested how it affected students’ performance on chemistry exams in their courses. The difference in average scores between the two groups (8.2 points for the experimental group and 6.4 points for the control group) was significant. Student feedback following the initiative was positive and encouraging. Most students indicated that learning chemistry with Avogadro was extremely helpful, bringing the microscopic world of molecules closer to them, and they felt that they would like to see such software integrated into their chemistry studies from day one. Other parameters will be tested in continuation of this study, such as students' attitudes toward learning chemistry and their inquiry skills.
World Journal of Chemical Education. 2017, 5(4), 136-141. DOI: 10.12691/wjce-5-4-4
Pub. Date: July 29, 2017
15631 Views4026 Downloads4 Likes
Gender Differences in Student Performance in First Semester General Chemistry in Fifteen Week and Five Week Semester Formats
Original Research
In this study we investigated both the overall student performance and the DFW rates (the number of students receiving a grade of “D”, “F”, or withdrawing from a class) for both males and females in first semester general chemistry courses over a period of five years. Data was collected from a large southwestern university in the for all of the first semester general chemistry courses offered during this period. The data included 12 fall semester sections, 16 spring semester sections and five summer semester sections with a total sample of 5384 students. The results showed that in the traditional fifteen week semesters the female students significantly outperformed the male students in both overall class averages (ANOVA p<0.001), and DFW rates (ANOVA p<0.001). However during the summer sessions a startling reversal occurred and the male students significantly outperformed the female students in both overall class averages (ANOVA p<0.05) and DFW rate (ANOVA p<0.001).
World Journal of Chemical Education. 2017, 5(4), 132-135. DOI: 10.12691/wjce-5-4-3
Pub. Date: July 20, 2017
9807 Views2951 Downloads
Bond-order and Magnetic Behavior of Diatomic Species without Molecular Orbital Theory
Book Chapter
In this chapter text based learning approaches has been highlighted by innovative and time economic way to enhance interest of students’ who belong to paranoia zone in Electronic Structure of Atoms and Molecules beneath Inorganic Chemistry of chemical science. In this pedagogical survey, I have tried to hub two (02) time economic pedagogies by including seven (07) new formulae in the field of chemical education. This chapter explores the results and gives implications for context based teaching, learning and assessment.
World Journal of Chemical Education. 2017, 5(4), 128-131. DOI: 10.12691/wjce-5-4-2
Pub. Date: June 19, 2017
22946 Views3647 Downloads
Quantum Dots, Part 1: Optical and Electrochemical Properties of CdTe Quantum Dots
Original Research
Quantum dots (QDs) are colloidal semiconductor clusters with physical dimensions in the range of several nanometers. Since the discovery of QDs in 1983, there has been a wide variety of research interest and activity. In particular, the mechanisms behind photoluminescence (PL) and electrogenerated chemiluminescence (ECL) and the applications of QDs have been extensively investigated. Bright fluorescence effect many analytical and technical applications: QDs have found promising applications as fluorescent biolabels [1,2], in optoelectronic and photovoltaic devices [3,4], and in light-emitting diodes (LEDs) [5,6]. This paper outlines some straightforward electrochemical and spectroscopic experiments with commercial CdTe QDs to explain their background mechanisms (e.g., electron-hole separation and recombination).
World Journal of Chemical Education. 2017, 5(4), 120-127. DOI: 10.12691/wjce-5-4-1
Pub. Date: June 12, 2017
17147 Views3622 Downloads2 Likes