JKPK (Jurnal Kimia dan Pendidikan Kimia)
Not a member yet
222 research outputs found
Sort by
Analysis of General Chemistry Textbooks Based on Multiple Representations of the Cell Potential Concept
Full text linkTextbooks 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.
Analysis of Chemistry Podcast Implementation in Learning Hydrocarbons and Petroleum for Inclusive Students
Full text linkThis research aims to conduct a feasibility analysis of a chemistry podcast, referred to here as “PodChem,” and to examine the impact of PodChem on learning hydrocarbons and petroleum. This study employs a pre-experimental method. The podcast media were developed using Anchor software and evaluated through a survey using a podcast media assessment questionnaire. The evaluation was carried out by lecturers as validators and students as podcast users. The assessed aspects include content, functionality, and appearance as complementary media in learning hydrocarbons and petroleum. The results indicate that the chemistry podcast PodChem was successfully produced using Anchor software. The findings suggest that PodChem is valid and suitable for educational use. The audio quality produced using Anchor is clear, and its accessibility is broad. Additionally, students reported that the content is relevant and enhances their understanding of the subject matter. Most students also found the podcast to be easily accessible and effective in conveying the concept. In terms of appearance, students agreed that the podcast title is engaging, the delivery is captivating, and the duration is appropriate. The implementation of PodChem in chemistry learning received positive feedback from students, with the majority accepting the use of podcast media in the classroom. Furthermore, 88.9% of respondents expressed a desire for podcasts to be used as complementary media in future learning, as they found podcasts to be more interesting, insightful, and easy to understand. These conclusions are supported by the results of student questionnaires and the assessment of assignments conducted by teachers in class
Green Synthesis and Characterization of 4'-Hydroxy-4-Nitro Chalcone using Grinding Techniques
Full text linkThe challenge of developing environmentally friendly synthesis methods for biologically active compounds remains a significant focus in green chemistry. This study aimed to synthesize 4'-hydroxy-4-nitro chalcone from 4-hydroxyacetophenone and 4-nitrobenzaldehyde using a grinding technique and then characterize the synthesized compounds. The 4'-hydroxy-4-nitro chalcone was synthesized via the Claisen-Schmidt grinding method for 45 minutes at room temperature. The grinding results were extracted with chloroform. The formed crystals were tested for purity by thin-layer chromatography (TLC), and further purification was carried out by recrystallization. The synthesized chalcone was characterized using FTIR, 1H-NMR, and 13C-NMR spectroscopy. The chalcone was also tested for antibacterial activity using the disc diffusion method against Staphylococcus aureus and Escherichia coli. The results showed that 4'-hydroxy-4-nitro chalcone could be successfully synthesized from 4-hydroxyacetophenone and 4-nitrobenzaldehyde using the grinding technique, yielding orangish-white crystals with a 70.63% yield and a melting point of 173°C. Purity was confirmed by TLC, and structural characterization was achieved through FTIR, 1H-NMR and 13C-NMR spectroscopy. Antibacterial testing revealed that the synthesized chalcone produced a clear zone diameter of 9.27 mm against S. aureus and 27.88 mm against E. coli. These results indicate that the compound has relatively strong antibacterial activity against E. coli and relatively weak activity against S. aureus. This study demonstrates the effectiveness of the green synthesis method and provides valuable insights into the antibacterial properties of 4'-hydroxy-4-nitro chalcon
Simultaneous Determination of Isoniazid and Pyridoxine Hydrochloride in Tablet Dosage Forms using Ratio Subtraction Spectrophotometry
Full text linkThe study focused on the simultaneous quantification of Isoniazid (INH) and Pyridoxine Hydrochloride (PRD) in tablet form, commonly used in antituberculosis treatments. Assessing the accurate concentration of both INH and PRD in tablets is vital to ensure their effectiveness, safety, and quality. Using the ratio subtraction spectrophotometry method, the study analyzed INH and PRD in Pehadoxin forte® tablets (batch no. 36057007, PT. Phapros, Indonesia), with 0.1 N HCl as the solvent. The method involved obtaining ratio absorption spectra by dividing the absorption spectra of INH and PRD, respectively, to derive zero-order spectra for each drug. Method validation parameters included linearity, accuracy, precision, Limit of Detection (LOD), and Limit of Quantification (LOQ). The results showed linearity values of 0.9985 for INH and 0.9988 for PRD. Accuracy was 98.1838% for INH and 100.0205% for PRD, while precision was 1.8769% for INH and 0.2037% for PRD. LOD and LOQ for INH were 0.8116 µg/mL and 2.7053 µg/mL, respectively, and for PRD, 1.3127 µg/mL and 4.3757 µg/mL. The levels of INH and PRD in the tablets were found to be 102.1157% and 101.3874%, aligning with the Indonesian Pharmacopoeia's standards. This methodological approach provides a reliable analytical tool for the simultaneous assessment of INH and PRD in tablets, potentially extendable to other drug combinations and formulations, thereby contributing to pharmaceutical quality control processes.
The Impact of Experimental Research-Based Learning Modules on Students' Affective Domain: A Study on Religious Moderation in Chemistry Education
Full text linkIslamic Religious Colleges (PTKI) 's key mission is to promote religious moderation for students. This aspect is currently missing in the Chemical Education Studies Program curriculum. To address this, we constructed a teaching module that applied the 4S-TMD method (Selection, structuring, characterization, and didactical reduction). This work is based on experimental data of using waste palm coconut shells as activated carbon for methylene blue dye adsorption, which formed two modules: Inorganic Chemistry II (Module A) and Instrumental Analysis Chemistry (Module B). The selection phase was designed with graduate learning outcomes (GLO), learning content, and indicators of religious moderation in module design. The item content validity index (I-CVI), measuring content validity, reached an excellent average of 0.98. During the structuring phase, laboratory experimental results were mapped conceptually. Module A performed excellently, with a validity of 85%, whereas Module B was below 80%. After the refinement steps, both modules reached 100% validity. The measure of the value of religious moderation of GLO indicates >60% for 10 variables, whereas the self-assessment of the nine values of religious moderation of students shows very good (above 20%). This is the first study applying religious moderation to chemistry education and showed that the 4S-TMD method of implementing the 4S-TS method was effective (4.9/5.0 for eligibility). Sow enjoyably integrates chemistry and science education with similar values, which can take place using their type
The Influence of Fe and Cr Dopant in the Synthesis of Ca3Co4O9 Thermoelectric Material on Crystal Structure, Crystal Size, Thermal Conductivity, and Electrical Conductivity
Full text linkIn this work, we study, by sol-gel method, CCO doped with Fe and Cr dopants, the implications for the aspects, crystal structure, crystal size, thermal conductivity, and electrical conductivity. Nevertheless, CCO has low thermoelectric efficiency and thus still longs for optimization in response to the performance, stability, and ecological environment requirement, which needs improvement. Dope would enhance the concentration of charge carriers without modifying the material structure itself. X-ray diffraction (XRD) to characterize the crystal structure and the Williamson–Hall (WH) method to calculate the crystal size were performed. SEM-EDS analyses provide surface morphology, particle size distribution, and elemental composition. The results show that the dopants change, among others, crystal size, microstrain, crystallinity index, and thermal and electrical conductivity, but no change in the crystal structure itself for any of these dopants. Fe doping increased the crystal size of CCO to 144.816 nm (versus 143.382 nm for pure CCO). Compared to Cr doping, the crystal's size was reduced to 65.232 nm. Where the estimated thermal conductivity increased for both dopants, attaining a value of 1.985967 W/mK for CCO-Fe and 1.952233 W/mK for CCO-Cr, concerning the value of 1.740633 W/mK of undoped CCO. Electrical conductivity also expanded (14.50 S/cm for CCO; 14.67 S/cm for CCO-Fe; 14.83 S/cm for CCO-Cr). These improvements highlight the potency of Fe and Cr dopants to fine-tune the CCO for thermoelectric usage
Optimization of Antibacterial Edible Film Formulation Based on Chitosan, Velvet Bean Ethanol Extract, and Cinnamon Essential Oil
Full text linkThe existing research on edible films as packaging materials has maintained that they are better in constituent materials, composition, and functionality. Due to their good bioactivity, edible films are utilized for packaging, which is considered bioactive. The recent study focused on using chitosan-velvet bean (Mucuna pruriens (L.) DC.) based edible bioactive packaging formulation for antibacterial activity. Velvet bean ethanol extract (V) accompanied by cinnamon (Cinnamomum burmannii (Ness) BL) essential oil (C) which is effective as an antibacterial against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923. Based on this study, the ascertained concentrations of V and C can generate the most optimum edible film associated with antibacterial activity and characterize the physical properties and morphology of the most optimum formulation of antibacterial edible film. It was proved that by addition of 30% V and 3.0% C, the most optimum edible film can be produced, which has maximum antibacterial activity against E. coli ATCC 25922 (19.36 mm strong) and S. aureus ATCC 25923 (18.94 mm strong). Moreover, this formulation boosts the thickness, tensile strength, and solubility of the film and simultaneously reduces the film's elongation, WVTR, and WVP. The edible bioactive packaging formulation produced thickness, tensile strength, solubility, percentage elongation, WVTR, and WVP values of 0.179 mm, 0.318 Mpa, 0.057%, 10.096%, and 3.747 g/m2.d, 8.586 g/m.d, respectively. The surface of the edible film still had some degree of porosity and texture, according to the morphology
Chitosan Crosslinking from Clam Shells (Cerithidea obtusa) with Tripolyphosphate for Cadmium (II) Adsorption
Full text linkThe study investigates chitosan crosslinking from clam shells (Cerithidea obtusa) with tripolyphosphate for cadmium (II) adsorption. Chitosan was prepared by deacetylating chitin using 60% NaOH and heating at 140°C for 60 minutes. Chitin was isolated from Cerithidea obtusa shells, an abundant waste in East Kalimantan. Crosslinking of chitosan with tripolyphosphate was synthesized via gelation methods, dissolving 5 g of chitosan in acetic acid and adding 0.1% tripolyphosphate as a crosslinker. The chitosan-tripolyphosphate characterization was conducted using FTIR, XRD, and SEM. FTIR spectra revealed an N-H vibration at 1635 cm−1, NH3+ deformation at 1534 cm−1, C-O stretching at 1072 cm−1, and P-O vibration at 1026.91 cm−1, indicating the presence of tripolyphosphate in chitosan. The XRD pattern showed broad peaks at 19.85° and 23.50°, characteristic of amorphous chitosan-tripolyphosphate. SEM images depicted a flat sheet without pores and a tight surface. Cadmium (II) adsorption on chitosan-tripolyphosphate at an optimum pH of 4 followed a pseudo-second-order kinetic model. It adhered to the Langmuir isotherm model, with a maximum adsorption capacity of 27.8 mg/g. The results demonstrate that chitosan crosslinked with tripolyphosphate effectively for cadmium (II) adsorption
Synthesis and Characterization of Polyaniline/CuO Nanocomposites with Various Temperature
Full text linkPolyaniline (PANI) metal oxide composites are known for their high electrical conductivity, environmental stability, and enhanced mechanical strength, making them valuable in applications such as sensors, batteries, and electromagnetic shielding. This study focuses on synthesizing and characterizing PANI/CuO nanocomposites to examine their structural, morphological, and functional properties at different synthesis temperatures. By integrating the conductive polymer PANI with copper oxide (CuO), a p-type semiconductor with a narrow band gap, the material’s capabilities are significantly enhanced. The oxidative polymerization of aniline, the process by which PANI is formed, requires precise control of oxidizing agents and reaction conditions, as these factors directly affect the polymerization, conductivity, and overall properties of the resulting nanocomposite. The PANI/CuO nanocomposites were synthesized at three different temperatures: 10℃, 25℃, and 50℃, to determine how temperature affects their characteristics. Fourier Transform Infrared (FTIR) spectroscopy and Scanning Electron Microscopy (SEM) were employed to analyze these nanocomposites. FTIR results revealed shifts in the quinoid and benzenoid rings, indicating hydrogen bonding between the NH group of PANI and the CuO surface, which accelerates charge transfer. The SEM analysis showed that while pure PANI exhibits a uniform globular morphology, the PANI/CuO nanocomposites display a nanorod morphology. These morphological differences impact the surface area and electrical conductivity of the composites, highlighting the significance of temperature in tailoring the material's properties for specific applications
In Silico Analysis of Antibacterial Activity of Fatty Acids in Swietenia humilis Zucc. Seed Extract Against Staphylococcus aureus sortase A enzyme
Full text linkThis study utilised molecular docking to predict the binding affinity of various fatty acids (FAs) found in Swietenia humilis to the sortase A (SrtA) protein target from Staphylococcus aureus. Binding energies, measured in kcal/mol, indicated the strength and stability of ligand-protein interactions, with lower values signifying stronger binding. The binding affinities of eight FAs as the active constituents in n-hexane extract of S. humilis and the positive control, gentamicin, were compared to assess their theoretical antibacterial activity. Palmitoleic acid exhibited the strongest binding affinity (-5.6 kcal/mol) among the FAs, suggesting the highest potential antibacterial activity, followed by linoleic, palmitic, linolenic, arachidic, tricosanoic, stearic, and oleic acids in decreasing order of affinity. Despite having weaker binding energies than gentamicin, a common gram-positive inhibitor from aminoglycoside derivative, FAs showed multiple hydrogen bonds and van der Waals interactions with key residues like ARG197, VAL168, VAL166, and ILE182, contributing to their binding stability. Palmitoleic acid formed multiple hydrogen bonds (ARG197 and GLY119) and significant van der Waals interactions, highlighting its strong theoretical binding. Stearic and oleic acids, although having higher binding energies, also formed critical hydrogen bonds, suggesting moderate potential activity. Gentamicin's single hydrogen bond suggests a highly specific binding site, which may result in high antibacterial activity despite fewer interaction points. The study indicated that FAs like palmitoleic and oleic acid show substantial potential as supplementary antibacterial agents, especially in the context of combating antibiotic resistance. This finding can pave a path for drug design and development to address the S. aureus's resistance