Jurnal Pendidikan Kimia
Not a member yet
236 research outputs found
Sort by
Effectiveness of a Problem-Based Learning Model Integrated with Socio-Scientific Issues to Improve Science Process Skills of High School Students
Get PDFProblem-Based Learning (PBL) integrated with SSI (SSI-integrated PBL) is a learning model used to enhance science process skills based on the context of 21st-century skills. This study intends to investigate the difference in science process skills between students taught by using SSI-integrated Problem-Based Learning and those taught by using Problem-Based Learning on salt hydrolysis. Four classes (N = 136) at a high school in Mandau were the study participants. This study used two treatments: the experimental group using SSI-integrated Problem-Based Learning (PBL) and the control group using Discovery Learning (DL). Relevant data were collected using the science process skills instrument. The data were analyzed using ANOVA. The finding was confirmed for the PBL model with science process skills, with a significance value of < 0.05. Looking at the mean value, the average for students who take PBL differs from that of students who take DL. The PBL model in the experimental class can enhance science process skills better than in the control class. The study's findings were compiled via discussion of the literature review and recommendations process. The SSI-integrated PBL approach is significantly better than the DL model in enhancing science process skills. The percentage of the contribution of SSI-integrated PBL to science process skills is 8.9%, which shows a high influence
Effect of Phosphoric Acid (H3PO4) Activation on the Preparation of Activated Carbon from Gymnostoma Rumphianum Wood
Get PDFThe utilization of Roya wood branches (RWB) as raw material for activated charcoal production has not yet been optimized in North Sulawesi, specifically in Wulauan Village, North Tondano District. This study aims to present the results of the analysis of the physical and chemical properties, X-Ray Diffraction (XRD), and Transmission Electron Microscope (TEM) of RWB-based activated charcoal. The production of activated charcoal was conducted in three stages: sample preparation, pyrolysis of RWB at a temperature of 365°C for approximately 3 hours, and activation of RWB charcoal using phosphoric acid (H₃PO₄) at concentrations of 1%, 2%, and 3% for 24 hours. The analysis of physical and chemical properties of both non-activated and H₃PO₄-activated RWB activated charcoal showed that the best quality was obtained at a 3% activator concentration, with a moisture content of 0.1683%, ash content of 2.3321%, volatile matter content (VMC) of 0.9429%, fixed carbon (FC) content of 96.7250%, and iodine adsorption capacity (IAC) of 10,535 mg/g, all of which meet the SNI 06-3037-1995 for activated charcoal. XRD analysis showed that non-activated RWB charcoal had three broad diffraction peaks in the ranges of 9–14°, 20–25°, and 35–50°, along with one sharp peak in the range of 25–30°. After activation with H₃PO₄, only three broad diffraction peaks were observed at 9–14°, 20–25°, and 35–50° for all three H₃PO₄ concentration variations.TEM analysis indicated that non-activated RWB charcoal had particle sizes ranging from 20–33 nm, while after activation with 1% H₃PO₄, the particle sizes ranged from 41–51 nm.
The Effect of Paras Stone Green Coagulant Preparation and Test Solution Concentration on Azo Dye Removal
Get PDFParas Stone, a volcanic clay rich in silica (SiO₂) and widely used in Lombok, West Nusa Tenggara (NTB), for sculptures, tombstones, and decorative ornaments, produces significant residual waste during carving. This waste can be repurposed as a natural coagulant for wastewater treatment, though research on its local application remains limited. Azo dyes, particularly prevalent in the textile industry, are produced at an estimated 700,000 tons annually, with 10–15% discharged into wastewater streams, posing serious environmental risks due to their toxic and non-biodegradable nature. This study investigates the removal efficiency of Remazol Red azo dye using Paras Stone under three conditions: non-activated, physically activated, and chemically activated with HCl or H₂SO₄. Chemical activation involved immersing Paras Stone in 3 M HCl or 0.1 M H₂SO₄ solutions with stirring for 2 hours, then rinsing to neutral pH and drying. Coagulation–flocculation experiments were conducted in batch mode, consisting of a 4-minute and 20-minute coagulation phase. The results demonstrated that non-activated Paras Stone achieved the highest dye removal efficiency (95.50%), surpassing samples activated with HCl (91.57%) and H₂SO₄ (92.53%). ANOVA analysis confirmed these differences as statistically significant at the 95% confidence level. The optimum conditions were obtained with a coagulant dose of 2.75 g of Paras Stone and 2.00 g of Opuntia ficus-indica gel, applied at a Remazol Red solution concentration of 30 mg/L. The O. ficus-indica gel, prepared by extracting parenchyma tissue, grinding, centrifuging, and collecting the gel-like supernatant, was a natural flocculant that facilitated the formation of larger flocs and accelerated sedimentation. These findings indicate that non-activated Paras Stone offers an effective, low-cost, and environmentally sustainable alternative for removing azo dyes in textile wastewater treatment
Nanocellulose for Military Textiles: Innovations, Applications, and Challenges
Get PDFMilitary textiles must withstand ballistic threats, high temperatures, and chemical exposure while remaining lightweight, durable, and multifunctional. Nanocellulose, especially cellulose nanofibrils (CNF) and cellulose nanocrystals (CNC), offers high specific strength, biodegradability, and tunable surface chemistry, making it a promising complement to conventional high performance fibers such as aramid. This structured review synthesizes peer reviewed studies published from 2015 to 2025 and retrieved from Scopus, Web of Science, and ScienceDirect, focusing on ballistic resistance, flame retardancy, and antibacterial functionality. Evidence shows that CNF and CNC reinforcement improves energy dissipation networks and strength to weight ratios, with several composites approaching aramid based benchmarks. For flame protection, nanocellulose coatings and hybrid layers reduce peak heat release rates by up to 38% and promote dense char barriers that limit heat and mass transfer. Antibacterial performance is typically achieved through functionalization with Ag, ZnO, or chitosan, often delivering over 90% inhibition of Escherichia coli and Staphylococcus aureus. Key barriers include production cost and scalability, moisture sensitivity that can reduce long term durability, and weak interfacial compatibility with aramid and ultra high molecular weight polyethylene (UHMWPE). Future work should prioritize scalable green manufacturing, interface engineering for durable hybrids, and validation under military relevant durability and laundering standards. Overall, nanocellulose is a strong candidate for next generation sustainable military textiles
Unveiling Students' Understanding of Ammonia as a Weak Base through Scaffolding-Based Chemical Reasoning Assessment
Get PDFReasoning is a basic cognitive ability in science learning, especially in chemistry, in which students must connect macroscopic, symbolic, and microscopic levels. However, most students seem to have difficulty learning chemical reasoning, especially in the ionization of weak bases (examples: NH₃). This study uses a scaffold-based assessment to evaluate students' explanations for ammonia as a base. A paper-and-pencil test was applied to 91 first-year preservice chemistry students to test them on phenomenological, mechanical, and structural types of reasoning. Two raters rated responses, and scoring reliability was assessed using Cohen’s Kappa (0.925). The data analysis consisted of descriptive statistics, correlation analysis, clustering (K-Means and t-SNE), and regression prediction with XGBoost. The results demonstrate that structural reasoning exhibits the highest level, but phenomenological reasoning has the most variation. There appears to be a high correlation between phenomenological empirical generalization and structural reasoning (r = 0.35+). Clustering outputs show three categories of students: high (R3), moderate (R2), and low (R1) reasoning, and most of the students are categorized at the moderate reasoning level, indicating some misconceptions. The XGBoost model performs well in predicting high-reasoning students but not in the moderate-reasoning classification. This paper indicates the power of scaffolding-embedded assessment for deducing reasoning patterns and misconceptions in ammonia ionization. The results can guide adaptive learning approaches for improving students' chemical reasoning
Characterization of SiO₂/C Composites from Bamboo Leaves and Graphite for Lithium-Ion Battery Anode
Get PDFSilicon dioxide (SiO₂) is a key component found in various biomass materials, including bamboo leaves. This study aims to synthesize SiO₂/C composites using bamboo leaves as the silica source and graphite as the carbon source, targeting their application as anode materials in lithium-ion batteries (LIBs). Silica particles were first prepared using the sol-gel method and characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). The SiO₂/C composite was synthesized through a solid-state reaction by mixing SiO₂ and graphite in varying SiO₂ weight percentages of 0%, 5%, 20%, and 100%, followed by calcination at 500 °C for 30 minutes under argon atmosphere. The morphology and composition of the resulting composites were analyzed using SEM-EDX. These composites were then employed as anode materials in LIBs, paired with a nickel manganese cobalt oxide (NMC) cathode. Electrochemical performance was assessed using a battery analyzer, and charge-discharge cycle (CDC) data were obtained. The addition of carbon significantly improved the electrochemical performance. Specifically, the composite with 100% SiO₂ showed a low capacity of 9.88 mAh/g, while those with 5% and 20% SiO₂ demonstrated significantly enhanced specific capacities of 97.35 mAh/g and 129.34 mAh/g, respectively, after five cycles
Molecular Docking Study of Active Compounds in White Radish (Raphanus sativus L.) on Cyclooxygenase-2 (COX-2) Receptor as an Anti-Inflammatory Agent
Get PDFInflammation is a natural endogenous response to injury, infection, or external stimuli, and it plays a critical role in the pathogenesis of various diseases, including arthritis and osteoarthritis. Despite their effectiveness, the long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs) often leads to several adverse effects, particularly gastrointestinal complications. Therefore, it is crucial to explore safer alternative therapies. This study aimed to evaluate the potential of bioactive compounds found in white radish (Raphanus sativus L.) as alternative anti-inflammatory agents using in silico molecular docking analysis against the cyclooxygenase-2 (COX-2) enzyme. Molecular docking simulations were performed using AutoDock Vina software, with the COX-2 structure obtained from the Protein Data Bank (PDB ID: 4PH9). The docking results indicated that glucoraphanin and squalene exhibited strong binding affinities with binding energies of –8.53 kcal/mol and –8.62 kcal/mol, respectively. Glucoraphanin was found to form hydrogen bonds with key active site residues similar to the interaction observed with ibuprofen, a standard NSAID. Meanwhile, squalene predominantly engaged in hydrophobic interactions with the enzyme. These findings suggest that glucoraphanin and squalene have the potential to act as effective COX-2 inhibitors and could serve as safer alternatives to conventional NSAIDs. However, further in vitro and in vivo studies are essential to validate their therapeutic potential and safety profiles
In Silico Pharmacokinetic and Microbiota-Integrated Profiling of Resveratrol Analogs
Get PDFResveratrol, a polyphenolic compound, possesses extensive biological activities; however, its use in clinical applications is restricted due to its poor bioavailability and rapid metabolism. In the present work, resveratrol and 14 of its structural analogs were screened by a combined in silico methodology. The methodology integrated density functional theory (DFT) calculations, quantitative structure–activity relationship (QSAR) modeling, physiologically based pharmacokinetic (PBPK) simulations, and microbiota-associated interaction considerations. Molecular descriptors were generated from optimized geometries at the DFT level of theory to predict permeability and metabolic characteristics. PBPK modelling was used to simulate the distribution of compounds in different physiological states. In contrast, bioinformatics analysis was used to support the gene expression modulation and the response of the microbial community to the analog structure. Several analogs predicted permeability and metabolic stability significantly better than native resveratrol. Furthermore, some compounds exhibited good associations with gut microbiota and metabolic pathways that may have regulatory functions. The results indicate that certain resveratrol analogs are potential drug candidates for further in vitro and in vivo studies. Furthermore, we report a full computational framework to aid the discovery of rational bioavailable polyphenol-related drugs
An Augmented Reality-Based Interactive Flipbook to Foster Conceptual Change in Learning Chemical Reaction Rates
Get PDFThis study developed and evaluated an Augmented Reality (AR) based interactive flipbook for grade 11 chemical reaction rate material, focusing on validity, practicality, and initial effectiveness in reducing misconceptions and promoting conceptual change. The study employed Research and Development (R and D) using a modified 4D model limited to the define, design, and develop stages. Participants were grade 11 high school students who had previously learned reaction rates. Content and construct validity were examined by chemistry education experts, learning media experts, and chemistry teachers. Practicality was assessed through student response questionnaires and observations of student activities during learning. Effectiveness was measured using a three tier diagnostic test, with pre and post results analyzed by the Wilcoxon test and effect size. Expert review indicated that the flipbook met validity criteria, with a mode score of at least 4 across all content and construct aspects. Practicality results were also high, reflected by a 90.11% questionnaire score and 95.87% activity observation. The intervention reduced average misconceptions by 55.72%, with a significant difference (p < 0.05) and a very large effect size (0.846). These findings suggest that AR integrated flipbooks can support visualization of abstract reaction rate concepts and facilitate conceptual change by targeting persistent misconceptions. Further studies with larger samples are recommended to improve generalizability
Analysis of General Chemistry Textbooks Based on Multiple Representations of the Cell Potential Concept
Get PDFTextbooks function as core learning resources in chemistry, particularly for explaining abstract ideas through visual representations. This study examines how the concept of electrochemical potential cells is represented in five college level general chemistry textbooks using five analytic criteria covering representation type, explicitness, connectedness, information sufficiency, and conceptual relatedness. The sample comprises widely adopted texts that span foundational topics to ensure relevance across common curricula. The analysis identified a distinct pattern within each category. Category C1 was dominated by symbolic representations at 74.7 percent. Category C2 showed predominantly explicit presentations at 79.3 percent. Category C3 reflected fully related and connected representations. Category C4 demonstrated complete presence of appropriate information at 100 percent. Category C5 included three levels of conceptual relatedness with quite related at 74.2 percent, not quite related at 19.4 percent, and not related at 6.5 percent. The findings outline the current quality of visual representations of potential cells in higher education materials and indicate areas where integration across macroscopic, submicroscopic, and symbolic levels could be strengthened. Educators, textbook authors, and curriculum developers can apply these insights to design materials that support deeper conceptual understanding and more coherent transitions between representations.