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Jurnal Akademika Kimia
Published by Universitas Tadulako
ISSN : 24775185     EISSN : 23026030     DOI : -
Core Subject : Science, Education,
Chemistry Education
Jurnal Akademika Kimia is an electronic open-access journal that aims to publish the latest research results in the area of chemistry education and pure chemistry from academicians, professionals, and other practitioners at all levels of chemistry education. The journal coverage includes the following: current trends of professional chemistry education, educational technology, teacher education, educational science, learning assessment, learning models and development of learning materials, as well as pure chemistry including organic chemistry, inorganic chemistry, analytical chemistry, physical chemistry, biochemistry and other chemistry fields such as environmental chemistry, that emphasis on a broad description of the general methods and processes for the synthesis, modification, and characterization of chemical materials.
Arjuna Subject : Kimia(semua kategori) - Kimia (Lain-Lain)
Articles 226 Documents
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Atmospheric Corrosion Inhibition of Steel Using Tea Leaf Extract in the Coastal Environment of Air Tawar, Padang Kurniawan, Niko; Saputra, Sabrizal; Dinalia, Dinalia; Yerimadesi, Yerimadesi; safitri, sauli
Jurnal Akademika Kimia Vol. 14 No. 2 (2025)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2025.v14.i2.pp123-131

Abstract

This study evaluates the effectiveness of tea leaf extract as a corrosion inhibitor for steel under real coastal atmospheric exposure. The novelty of this work lies in its direct assessment of a plant-derived inhibitor in an open-air marine environment, a setting that has not been adequately addressed in previous studies, which have largely focused on controlled aqueous systems. In addition, this study employs mature tea leaves, an abundant agricultural byproduct with naturally high tannin content, processed through a simple, solvent-free extraction method, thereby offering a sustainable route for green inhibitor development. The extract was obtained from mature tea leaves through aqueous boiling, and its tannin content was quantified using UV–Vis spectrophotometry. ASSAB 760 steel specimens were coated by immersion in tea extract at varying concentrations and soaking durations, followed by natural exposure in a coastal environment for 1 to 30 days. Corrosion behavior was evaluated using the weight loss method. The results showed that mature tea leaves contained the highest tannin concentration (29530.95 ppm), supporting their selection for inhibitor application. The optimum extract concentration was identified as 11000 ppm with a 5-hour immersion time. Under these conditions, treated steel exhibited a substantially lower corrosion rate (7.78 × 10⁻⁵ g/cm²/day) compared to untreated steel (1.66 × 10⁻⁴ g/cm²/day), corresponding to a maximum inhibition efficiency of 84.71%. The inhibition mechanism is attributed to the formation of a stable Fe³⁺–tannin chelate complex that adsorbs onto the steel surface, forming a protective film that restricts the ingress of aggressive chloride-rich moisture in the coastal atmosphere. Overall, the findings demonstrate the practical viability of mature tea leaf extract as an effective and environmentally benign atmospheric corrosion inhibitor, providing field-relevant insight into sustainable protection strategies for marine-exposed steel infrastructure.
A Study Compares The Effectiveness of Hydrochloric and Sulfuric Acids in Hydrolyzing Jackfruit Seeds into Bioethanol Ginting, Elfrida; Simatupang, Lisnawaty; Sembiring, Jhony H.
Jurnal Akademika Kimia Vol. 14 No. 3 (2025)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2025.v14.i3.pp174-180

Abstract

North Sumatera Province, known for its jackfruit production, presents an opportunity to explore jackfruit seeds as a viable bioethanol feedstock. The province’s diverse agricultural commodities generate substantial agricultural waste, currently primarily used as fertilizer. This research aims to diversify waste utilization by focusing on jackfruit, a prominent commodity in North Sumatera, and its potential as a bioethanol feedstock. Given the scarcity of fossil fuels, exploring renewable energy sources, such as bioethanol derived from agricultural waste, is crucial. Identifying accessible sources within regions is vital. Converting jackfruit seed starch into bioethanol requires hydrolysis. This paper compares hydrochloric and sulfuric acid for bioethanol production. Qualitative testing confirmed the presence of bioethanol from both acids. The density of bioethanol produced using hydrochloric acid was 0.825 g/mL, 3.4% higher than the Indonesian standard value. Similarly, the density of bioethanol produced using sulfuric acid was 0.894 g/mL, 12% higher than the standard value. The viscosity of bioethanol produced using hydrochloric acid was 1.02 cp, 12% lower than the standard value. In contrast, bioethanol produced using sulfuric acid had a viscosity of 1.04 cp, 11% lower than the standard value. FTIR spectra of bioethanol treated with hydrochloric acid showed five prominent peaks: 3339.88 cm-1 (OH), 2953.35 cm-1 (-CH), 1643.79 cm-1 (-C-C), 1450.75 cm-1 (-CH3), and 1014.17 cm-1 (-CO). FTIR spectra of bioethanol treated with sulfuric acid showed only two major peaks at 3339.46 cm-1 and 1635.42 cm-1, both corresponding to -OH and -CH. The NMR spectra show three distinct peaks. In ethanol’s proton NMR spectrum, the first doublet at 1.71 and 1.61 ppm is the methyl group protons. The second peak at 2.02 ppm is the hydroxyl group proton. The third doublet at 3.59–3.62 ppm is the methylene group protons. All methods indicate that hydrochloric acid is a more effective hydrolytic agent than sulfuric acid.
Effectiveness of Problem-Based Learning with Dr Stone Animation on Grade XI Students’ Acid-Base Learning Outcomes Jannah, Miftahul; Tiwow, Vanny M. A.; Abram, Paulus H.; Nurmayanti, Yuli
Jurnal Akademika Kimia Vol. 14 No. 3 (2025)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2025.v14.i3.pp181-186

Abstract

The background of this research is low student performance in the topic and the need for an innovative, interactive, and contextual learning approach. This study aims to examine the effectiveness of the Problem-Based Learning (PBL) model using Dr Stone's animation media on students' learning outcomes in the acid-base topic for Grade XI students at SMA Negeri 1 Sirenja. The problem addressed in this research relates to how to improve student learning outcomes and engagement through the integration of contextual and technology-based media. The research employed a pre-experimental design with a one-group pre-test and post-test on a single experimental class consisting of 30 students. The instruments used included Lesson Plans (RPP), Student Worksheets (LKPD), Dr Stone animation media, and a multiple-choice learning outcome test consisting of 15 validated questions, reviewed and approved by expert validators. The validation results showed that all instruments were valid and appropriate for use. Student learning outcomes were analysed using the N-Gain score to measure the improvement after learning. The average N-Gain score was 0.7331 (73.31%), placing it in the moderately effective category. The average difference between pre-test and post-test scores was 37.10 points, indicating a significant improvement in student learning outcomes. Most students experienced substantial learning gains after participating in problem-based learning supported by animation media. This study demonstrates that combining the Problem-Based Learning (PBL) model with Dr Stone's animation media effectively improves student learning outcomes. Furthermore, this study supports the learning process by incorporating a contextual and interactive approach that fosters students’ motivation, deepens their conceptual understanding, and promotes active involvement in chemistry lessons. It also offers valuable guidance for teachers on applying technology-integrated, student-centred teaching strategies in science education.
Effect of Ethyl Acetate and n-Butanol Fractions of Sonneratia caseolaris L.: Reducing Cholesterol Levels in Vitro Utami, Aditya P.; Prahasiwi, Masitoh S.; Indriyanti , Erwin; Anggoro, Aloysius B.; Wijayanti, Ifa R.; Rahman, Abdul
Jurnal Akademika Kimia Vol. 14 No. 4 (2025)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2025.v14.i4.pp226-233

Abstract

Hypercholesterolemia is an elevated condition of cholesterol levels in the blood above normal limits. Traditionally, Red Pidada plants (Sonneratia caseolaris L.) have been used as anti-hypercholesterolemic agents. This research aimed to determine the maximum concentrations, effects, and differences of the ethyl acetate and n-butanol fractions of Red Pidada rind in an in vitro study, using cholesterol activity as the endpoint; preliminary tests included phytochemical screening and TLC. Cholesterol levels were analysed using the Zak method at 468 nm. The results of the phytochemical screening and TLC were positive for flavonoids, phenolics, saponins, steroids, and tannins in the extract, ethyl acetate, and n-butanol fractions. Phytochemical screening and TLC show the presence of flavonoids, phenolics, saponins, steroids, and tannins in the extract, ethyl acetate, and n-butanol fractions. The maximum concentration of the ethyl acetate and n-butanol fraction that might decrease cholesterol levels was 300 ppm, with 62.40% ethyl acetate and 57.38% n-butanol. Data analysis using two-way ANOVA showed a significant effect (P>0.05), indicating that the ethyl acetate and n-butanol fractions lowered cholesterol levels. The post hoc test also showed a significant difference (P<0.05) between the ethyl acetate and n-butanol fraction groups.
Development of Problem-Based Learning E-Module Integrated with Scientific Literacy on Acid-Base Concepts for Grade XI Students Tarigan, Pasion; Herlinawati, Herlinawati
Jurnal Akademika Kimia Vol. 14 No. 4 (2025)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2025.v14.i4.pp260-265

Abstract

In learning chemistry, especially acid-base materials, students still have difficulty understanding abstract concepts and show low science literacy. Therefore, it is necessary to develop teaching materials in the form of e-modules based on Problem-Based Learning (PBL) integrated with science literacy to improve students' understanding of concepts and critical thinking skills. This study aims to: (1) Determine the level of validity of the e-module of chemistry learning based on PBL integrated with science literacy on acid-base material for grade XI SMA, (2) Determine student responses to the e-module of chemistry learning based on PBL integrated with science literacy on acid-base material for grade XI SMA. This type of research is research and development (R&D) with a 4D development model, but is limited to a 3D model. The stages carried out include the definition stage, to analyse things that need to be done, including front-end analysis, student analysis, task analysis, and concept analysis. The design stage is to design an e-module product on acid-based material. The development stage aims to validate the e-module that has been designed and revised based on the validator's suggestions, and then a practicality test is carried out based on student responses. The assessment instruments used in this study were validation questionnaires from material experts and media experts, as well as student response questionnaires. The assessment scale used was a Likert scale with a score range of 1-4. The results of the study showed that: (1) The average percentage of assessments given by material expert validators was 94.36% with a very valid category, while the average percentage of assessments given by media expert validators was 95.19% with a very valid category. (2) The results of the practicality test obtained from student responses obtained an average percentage value of 88.78%, with a very practical category.
Synthesis of Sodium Carboxymethyl Cellulose (Na-CMC) from Waste Peanut Shell via Alkalization and Carboxymethylation Process Nirvananda, Winny A.; Salsabila, Adellia E. S.; Kurniati, Ely
Jurnal Akademika Kimia Vol. 14 No. 4 (2025)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2025.v14.i4.pp194-203

Abstract

Peanut shell waste is abundant in Indonesia and contains high cellulose content; however, its use in the synthesis of sodium carboxymethyl cellulose (Na-CMC) has been minimally explored. Previous studies have primarily used biomass such as loofah fibers, corn stalks, and oil palm fibers, leaving a research gap in evaluating peanut shells as an alternative cellulose source. This study addresses that gap by examining how NaOH concentration and Na-MCA mass influence the quality of Na-CMC derived from peanut shell waste. Na-CMC was synthesized through alkalization and carboxymethylation, preceded by pre-hydrolysis, delignification, and bleaching to enhance cellulose purity. Experimental variations focused on optimizing reagent levels to achieve high product quality. The optimal condition, 20 % NaOH and 7 g Na-MCA, yielded Na-CMC with 94.81 % purity and a degree of substitution (DS) of 1.2137. A DS above 1.2 indicates adequate substitution of cellulose hydroxyl groups, improving water solubility and functional performance, making the product suitable for industrial use in textiles, adhesives, and paper. FTIR analysis confirmed successful carboxymethylation through the presence of –OH, –COO⁻, and –CH₂ groups. Excess reagent levels reduced purity and DS due to side reactions and cellulose degradation. This study demonstrates the potential of peanut shells as a sustainable, low-cost raw material for Na-CMC. It provides scientific insight into the optimization of Na-CMC synthesis from agricultural waste.
Development of Augmented Reality (Ar)-Based Interactive Digital Magazine Media for Class X Chemistry Bond Learning Sari, Sri A.; Damanik, Febby F.
Jurnal Akademika Kimia Vol. 14 No. 4 (2025)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2025.v14.i4.pp251-259

Abstract

Technological advancements demand innovation in learning media, particularly in the digital era. Chemistry lessons, such as those on chemical bonds, are often considered abstract and difficult for students to grasp. Therefore, engaging, interactive, and contextual learning media are needed. The use of interactive digital magazines based on Augmented Reality (AR) is expected to enhance conceptual understanding and student learning interest. The study successfully developed and tested an AR-based interactive digital magazine for teaching atomic bonding to Grade X learners, yielding highly positive results in terms of validity, effectiveness, and user satisfaction. The media achieved a validity score of 95.1% for material and 95% for media aspects, with an N-Gain score of 0.7964 indicating high effectiveness. Additionally, teacher practicality was rated at 93.74%, and learner responses reached 89.75%, both rated as very high, confirming the media's feasibility and effectiveness for studying atomic bonding concepts.
Influence of the PBL Model on Increasing HOTS and Students' Learning Motivation in Medan High Schools Panjaitan , Angel S.; Sitorus, Marham
Jurnal Akademika Kimia Vol. 14 No. 4 (2025)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2025.v14.i4.pp204-208

Abstract

This research is motivated by the continued use of conventional learning models (e.g., lectures) in instructional practice. In the learning process, it remains more teacher-centred, with students listening and receiving the material provided. This causes a lack of critical thinking and student motivation in learning. The purpose of this study is to determine the effect of the PBL learning model on improving HOTS and student motivation, and also to determine the effectiveness of the PBL learning model in improving students' HOTS. This research is a quantitative study with a quasi-experimental method. The study results indicate a significant improvement in students' HOTS, as evidenced by the pretest and posttest scores.
Development of PjBL-Based STEM E-Modules on Colloidal Materials Sihombing, Geby S.; Eddiyanto, Eddiyanto
Jurnal Akademika Kimia Vol. 14 No. 4 (2025)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2025.v14.i4.pp266-270

Abstract

The Industrial Revolution 4.0 demands improvements in the quality of education to produce superior human resources. In learning chemistry, especially colloid materials, students still have difficulty understanding abstract concepts and show low science literacy. This study aims to determine the needs analysis, the feasibility of e-modules, and the improvement of student learning outcomes using STEM e-modules based on project-based learning on colloid materials. This study was conducted at SMAN 1 Percut Sei Tuan and the sample class Matlanfor. The research method used is Research and Development (R & D), and the development model is ADDIE. Data collection is through interviews, observations, questionnaires, and tests. Data analysis of learning outcomes improvement uses the N-Gain test. The results obtained indicate that teachers have not maximised the use of the PjBL learning model and have never used PjBL-based STEM E-Modules; the books used do not contain projects or STEM. 77% of students reported feeling bored during the learning process because the media used or the teacher's teaching methods were less engaging. 92% need new teaching materials to improve students' knowledge of colloid learning through PjBL-based STEM E-Modules. The project-based learning (STEM) e-module on colloidal materials had a feasibility of 90.39%, categorised as very high, and was declared feasible. The learning outcomes of students who were treated with the PjBL-based STEM e-module increased by 72.47%.
Making Biochar from Palapi Wood Waste (Heritiera sp.) for Decolourisation of Dyes in Water Razni, Razni; Napitupulu, Mery; Walanda, Daud K.; Poba, Detris
Jurnal Akademika Kimia Vol. 14 No. 4 (2025)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2025.v14.i4.pp209-217

Abstract

Dye waste from industries such as batik can pollute the environment and endanger health because it is carcinogenic. One solution to handle this is to use biochar as an adsorbent, where in this study, the biomass used as biochar is palapi wood waste in the form of wood husks. This study aims to determine the adsorption capacity of biochar from palapi wood waste against indigsol blue and remazol yellow dyes with variations in weight, time, and pH. The method used in this study is the pyrolysis method, namely the process of heating biomass materials at high temperatures without or with little oxygen. Characterization was carried out by determining the water content, ash content, functional groups, and morphology of the biochar. Decolorization efficiency was analyzed using a UV-Vis spectrophotometer. The results showed that the water content at temperatures of 400 ℃, 450 ℃, and 500 ℃ were 11.9 %, 6.6 %, and 5.3 %, respectively. The ash content at the same temperature was 2.3 %, 7.5 %, and 8.7 %, respectively. The maximum weight with variations of 50, 75, 100, and 125 mg in adsorbing 2 dyes is 125 mg with an adsorption percentage of indigosol blue dye of 41% and remazol yellow dye of 42.9 %. The optimum time for biochar to adsorb indigosol blue dye is 50 minutes, with an adsorption percentage of 47.9, and remazol yellow dye for 40 minutes, with an adsorption percentage of 79 %. The optimum pH of indigosol blue and remazol yellow dyes by biochar occurs at pH 7, with an adsorption percentage of indigosol blue dye of 93.03 % and remazol yellow dye of 87.4 %. The absorption capacity of biochar for indigosol blue and remazol yellow dyes follows the Langmuir absorption isotherm of 0.9194 mg/g and 0.7954 mg/g, respectively.

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