African Journal of Chemical Education

Implementation of flipped classroom pedagogy to enhance students’ performance and retention of electron configuration concepts

2024-08-20T14:25:29+00:00

Electron configuration is a fundamental topic in chemistry education at the senior high school level such that failure to understand the basic concepts will gravely affect students’ comprehension of several other chemistry topics as they progress. This study investigated the implementation of flipped classroom pedagogy to enhance students' academic performance and retention of electron configuration concepts in a senior high school setting. The study, conducted at a selected Senior High Technical School in Ghana, addressed the prevalent issue of students' inadequate conceptual understanding resulting in low performance and retention of electron configuration concepts. Utilizing a single-group, a classroom action research design guided this study. The intervention involved a four-week implementation of the flipped classroom learning approach. The instrument used was test, which was developed in a form of pre- intervention test, post-intervention test and delayed post-intervention test. Participants were selected by purposive sampling, by engaging students in an intact class with the challenge of understanding electron configuration. The findings revealed a significant enhancement in students' academic performance in electron configuration due to application of the flipped classroom pedagogy. The study further found that the magnitude of the effect the flipped classroom pedagogy had on the students’ performance was large. The study also found that the flipped classroom pedagogy was effective in retaining electron configuration concepts among the students. Consequently, the study concludes that flipped classroom learning is a valuable pedagogical tool for improving students' academic performance and retention of electron configuration concepts in chemistry education. The study recommends the integration of flipped classroom methodology by chemistry teachers in teaching electron configuration and other chemistry topics in the selected school.

Proximate analysis, mineral compositions and in-vitro investigation of antidiabetic potential of methanolic leaf extract of Bryophyllum pinnatum

2024-08-20T14:50:02+00:00

Bryophyllum pinnatum has generated a great deal of interest in the scientific world due to its numerous benefits. The proximate content, mineral composition, and antidiabetic potential of the methanolic leaf extraction were evaluated. The proximate content was evaluated in a fresh sample to determine the ash, carbohydrate, fat, fiber, protein, and moisture using the method of the Association of Analytical Chemists (AOAC), and mineral composition was done using an atomic absorption spectrophotometer (AAS). The in vitro method was used to determine the antidiabetic potential of the leaf by evaluating the inhibitory activity of the leaf extract on alpha-amylase and alpha-glucosidase, respectively. The result shows that Bryophyllum pinnatum contains (0.63 ± 0.05%) ash, (3.72 ± 1.37%) carbohydrate, (1.13 ± 0.32%) lipid, (3.90 ± 0.26%) fiber, (2.33 ± 0.472%) protein, and (88.08± 1.34%) moisture in fresh samples. The result of the mineral content revealed that Bryophyllum pinnatum is a good source of minerals such as ‘Fe, Zn, Cu, Mg, Na, K, Ca, Mn, Se, and Co. Furthermore, the antidiabetic potential of the leaf showed that at various concentrations of the leaf extract, there was an appreciably level of inhibition on both alpha-amylase and alpha-glucosidase, respectively. This research shows that Bryophyllum pinnatum leaf is a good source of human nutrition and should be included as a dietary supplement. The leaf can also be used in the treatment or management of diabetic-related issues.

Preliminary design of learning material on Kolbeschmitt reaction mechanism visualized by crystal data

2024-08-20T15:04:47+00:00

In order to educate introductory chemistry, both imagining and visualizing the structures of molecules and complex ions have been considered to be of significance for learners. Some of sodium phenoxide (NaOPh), common compound in organic chemistry as a reactant of the well-known industrial process, ‘Kolbe-Schmitt reaction’, have unique crystal structures including square units consisting like “cubane” form. Sodium salicylate is a product of the reaction, and its crystal structure was reported recently. However, this fact is seemed to be almost unknown in chemical education. Therefore, I report a study herein about the possibility of crystal structural data available in the Cambridge Crystallographic Data Centre (CCDC) as potential learning material in chemical education. Consequent searched some crystal structures; it was found that pure NaOPh crystal has rigid polymer chain structures involving four-membered square Na₂O₂ unit. On the other hand, others have structures with one or several crown ethers or solvent molecules. The crystals of NaOPh coordinated by several solvent molecules are indicating as if they are in the dynamic reacting process with solvation, in spite of that they indeed are in solid state. Regrettably, there seemed no exact crystal data of NaOPh solvated with CO₂ itself. Instead, combined with the crystal structure of the product, i.e., sodium salicylate, a reaction mechanism could be speculated. When teaching chemistry, these crystallographic data would be effective enough to explain the dynamic reacting process of the Kolbe-Schmitt reaction for students with their impression.

Separation and identification of transition metal ions by paper chromatography: improved qualitative inorganic analysis

2024-08-21T06:42:51+00:00

Paper chromatography (PC), a set of low-cost, straightforward experiments has been designed to teach the fundamentals of chromatography to undergraduate students studying introductory inorganic chemistry. These experiments detect and separate metal ions belonging to different groups in the analytical table. Through these PC experiments, undergraduate students will learn about the separation and identification of metal ions from various metal salts, the comparison of color spots and retention factor values during the separation of metal ions, the impact of alkalinity during the oxidation of metal ions, among other ideas. Paper chromatography (PC) and planar chromatography both use immobile phases that are solid, plane surfaces. A specific type of paper is used in these experiments as the stationary phase (Whatman quantitative grade 41 filter paper). A very small amount of sample is used for this qualitative study. Using various eluting agents, PC may be utilized to separate, identify transition metal ions (Fe³⁺ & Cr³⁺) in the analytical group III, (Pb²⁺& Cu²⁺) in group II, (Co²⁺ & Ni²⁺) in group IV, (Co²⁺ & Cu²⁺) in group (IV) and group (II) and (Mo⁶⁺ & W⁶⁺) in the group VI based on their colorful spots and retention factors (Rf) values. This qualitative study facilitated undergraduate students to realize the impact of PC to identify and separate pair of metal ions through different color spots and their retardation factor (Rf) values.

Assessment of potable water quality control checks in the Gambia

2024-08-21T06:53:03+00:00

This study looked at potable water quality control checks, specifically with regards to locally produced bottled water in The Gambia. Questionnaires were distributed to the Food Safety and Quality Authority and seven out of eight existing bottled water producers in The Gambia. The surveyed companies used four different methods of disinfection. All the companies used boreholes as their source of water. The Food Safety and Quality Authority carries out a satisfactory level of inspection of the surveyed companies, which in turn generally comply with the standards. There is need for a comprehensive pesticide analysis in potable water in The Gambia.

Prospective physics-chemistry secondary teachers’ knowledge of the different levels of representation in chemistry

2024-08-21T07:09:51+00:00

Chemistry concepts are described at macroscopic, sub-microscopic and symbolic levels. This paper aims to evaluate the prospective physics-chemistry secondary teachers’ (PPCTs) knowledge of the multiple levels of representation in chemistry. A quantitative study using a cross-sectional test was conducted on forty-eight participants. Results show higher trainee achievement at the macroscopic level. The order of acquisitions remained very similar for definitions and examples (Macro > Sub-Micro > Symbolic). Both chemistry (6.67%) and physics (6.45%) license graduates have scored close percentages to define the symbolic level. PPCTs are suffering conceptual difficulties to give examples illustrating each level of representation in chemistry. The highest level of knowledge concretization is in favour to chemistry license. Females perform three times more than males at the macroscopic level. PPCT performances increase with post-license training.

Relevance of the 1,2,4-trioxane ring in the leishmanicidal activity of artemisinin and derivatives: a computational study

2024-08-21T07:17:09+00:00

In this manuscript, one of the approaches that have been used in teaching Computational Chemistry to undergraduate chemistry students is reported. The topic Neglected Tropical Diseases (NTDs) was used as a motivating element, a disturbing subject in several regions of the world, including Brazil. Artemisinin (1) and derivatives (2 and 3) from the literature, with different degrees of leishmanicidal activity, are computationally investigated to unravel the relevance of the 1,2,4-trioxane ring in its biological actions. Initially, different theoretical approaches were investigated to establish the most adequate theory/atomic basis (B3LYP/6-31G**) for the development of the study. Subsequently, molecular electrostatic potential (MEP) and molecular orbitals (MOs) approximations were used in an assumption to identify key structural features of compounds necessary for their leishmanicidal activities, as well as to investigate likely interactions with the receptor in a biological process. In addition, to discover the best geometry involving the studied ligand-receptor complexes and to help in the investigation of the theme on screen, simulations of interactions between the endoperoxide bridge region of the 1,2,4-trioxane ring of the compounds and the Fe2+ ion of the receptor (heme) were performed. The investigation with MEP showed that the compounds (1 and 2), which have the 1,2,4-trioxane ring, can undergo electrophilic attack in this region, mainly due to the existence of the endoperoxide bridge, unlike the compound (3) which missed this bridge. The scrutiny carried out with the MOs, was anchored in information from the literature, indicating that the HOMO of the compounds (1 and 2) can interact with the heme in the occurrence of a biological process. Besides that, the study of ligand-heme interaction, in addition to indicating specific interactions between the endoperoxide bridge of the 1,2,4-trioxane ring and Fe²⁺ heme, corroborated the finding that the loss of this bridge directly influences the loss of the leishmanicidal activity of one of the derivatives (3). The motivating topic NTDs, along with the topics Methodology, Results and Discussion, as well as the Conclusions and References presented in this manuscript constitute a robust exercise that can help in the development of competence in Computational Chemistry in Chemical Education (undergraduate and postgraduate).

Enhancing chemistry education: Implementation of ceramic cleaner and laundry soap making to foster subject interest among secondary school students

2024-08-21T07:35:27+00:00

The integration of practical learning components is crucial in promoting students' interest in STEM education, improving the application of acquired competencies, and achieving learning outcomes. This study was carried out to investigate the impact of integration of practical application on students’ subject interest. The study employed a quantitative approach with posttest-only control group designs. It randomly assigned 205 respondents to control and experimental groups. To ensure similarity between groups, block randomization based on characteristics such as prior exposure to ceramic cleaner and laundry soap activities, Academic performance and parents’ occupations were used. It involved random sampling of schools (N = 4) and purposive sampling of Form four science students (N = 205). A Likert scale questionnaire was used to collect data. An independent sample ttest was used in data analysis. An independent sample t - test revealed a significant mean difference between the control group (N1 = 3.6) and the experimental group (N2 = 4.4). The experimental group showed considerably more interest in the subject than the control group (t = -9.199, p < .001, effect size 0.29). This study recommends that educators prioritize strongly the practical application of chemistry in everyday circumstances to improve students' interest in chemistry and persistence in STEM education.

Investigating how chemistry teachers in Grade 11 utilize the periodic table of elements to facilitate the learning process of writing and balancing chemical equations

2024-08-21T07:44:14+00:00

The periodic table of elements is central to the study of chemistry and other disciplines of science, yet Namibian learners do not perform satisfactorily in topics which require its use in answering questions. The purpose of this study, therefore, was to explore how Grade 11 chemistry teachers make use of the periodic table of elements to mediate the learning of writingand balancing chemical equations. The study was carried out with two chemistry teachers in two rural schools in the northern partof Namibia. It was underpinned by an interpretive paradigm, within which a qualitative case study approach was employed. Data were collected through in-depth interviews (semi- structured) and observations. Shulman’s Pedagogical Content Knowledge is used as theoretical framework in this study and the data sets were analyzed using the three of the five Topic Specific Pedagogical Content Knowledge (TSPCK) components adapted from Mavhunga and Rollnick. The findings revealed that teachers demonstrated positive attitudes towards the use of the periodic table of elements when teaching the writing and balancing of chemical equations. However, challenges regarding inadequate materials that hindered the teaching and learning process were observed. Another finding of this study was that teachers used a variety of mediation tools such as prior knowledge and appropriate representations to enhance learning. The study therefore recommends continuing professional development for chemistry teachers in order to provide teachers with opportunities and spaces to share subject matter knowledge, pedagogical content knowledge, and easily accessible resources that they can use to improve chemistry classroom instruction.

Incorporating real-life context into school chemistry enhances meaningful learning

2024-08-21T07:54:52+00:00

This policy brief describes the importance and significance of incorporating real-life contexts into school chemistry for enhancing students’ meaningful learning.

Call for papers on chemistry in stem education

2024-08-20T14:06:16+00:00

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