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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 201 Documents
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Synthesis and Characterisation of B-CDs/TiO2 Composite Anthoni B. Aritonang; Ajuk Sapar; Uswatun Hasanah; Adhitiyawarman Adhitiyawarman; Puji Ardiningsih
Jurnal Akademika Kimia Vol. 11 No. 4 (2022)
Publisher : Universitas Tadulako

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Abstract

Synthesis of composite boron-doped carbon nanodots (B-CDs)/TiO2 using the sol-gel method performed with titanium tetraisopropoxide (TTIP) precursor and B-CDs prepared by the microwave method using citric acid monohydrate, urea, and boric acid as precursors. The optimum concentration of boron dopant (B) on B-CDs/TiO2 is 0.5% boron (w/w) which is then used as a composite on TiO2 resulting in a brown solid and has blue luminescent under UV light. The result with UV-Vis/DRS for variation in B-CDs concentration of 0.5%, 1.25%, and 2.5% showed Eg values of 2.34 eV, 2.00 eV, and 2.29 eV. B-CDs cause the maximum emission peak (λEm) to redshift and affect the intensity of photoluminescence TiO2. The characterization of FT-IR does not indicate a new peak, there is no bonding in the B-CDs/TiO2 composite. The TiO2 diffractogram was observed to shift towards a larger 2θ which caused the crystallinity of TiO2 to decrease. Based on the photocatalytic activity test on the degradation of methylene blue solution, it showed fairly good activity. It is expected that the B-CDs/TiO2 composite has the potential to be applied as a photocatalyst to degrade organic pollutants under visible light illumination.
Utilization of Hyperdocs in Online Learning Models on Student Learning Outcomes Hasmawati Hasmawati; Daud K. Walanda; Afadil Afadil; Kasmudin Mustapa; Detris Poba
Jurnal Akademika Kimia Vol. 11 No. 4 (2022)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2022.v11.i4.pp261-265

Abstract

This study aims to improve student learning outcomes through online learning models by utilizing hyperdocs on buffer solution material in class XI MAN 1 Palu City. This type of research uses a quasi-experiment with a pretest and posttest Group Design. Quantitative descriptive research with mixed methods and sampling by purposive sampling. The sample in this study were students of class XI MIPA 1 as the experimental class and XI MIPA 3 as the control class. The instrument used in this study was a learning achievement test totaling 16 multiple-choice question numbers. The research results were obtained from both classes, namely for the experimental class of 81.14 and the control class of 77.05. Learning outcomes were analyzed by testing the effect size for the experimental class, namely 1.2 (Very Large) and 1.0 (Large) for the control class. Based on the results of the study it can be concluded that the online learning model by utilizing hyperdocs in class XI MAN 1 Palu City students can improve student learning outcomes.
The Processing of Glycerol with Acetone to Produce Solketal Using Amberlite IR 120 Na Catalyst: Comparison of solketal Production Using Gas Chromatography Fikrah D. I. Sawali; Hary Sulistyo; Wahyudi B. Sediawan; Moh. A. Afandy
Jurnal Akademika Kimia Vol. 11 No. 4 (2022)
Publisher : Universitas Tadulako

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Abstract

Solketal is a chemical that can be made by combining glycerol with acetone. This compound can be used as a fuel oil additive to improve the cold flow properties of liquid transportation fuels, reduce specific emissions, aid in the reduction of gum formation (oil sap), increase oxidation stability, and increase the octane number by up to 2.5 points to accelerate the initiation process in motor fuel combustion. The addition of solketal, a bio-additive material in biodiesel, is expected to reduce emissions from diesel engines. Solketal can reduce glycerol waste created from biodiesel synthesis in addition to reducing resultant emissions because glycerol waste can be used as the primary raw material in the process manufacture of the solketal. The purpose of this research is to find out The catalytic process of glycerol and acetone using Amberlite IR 120 Na catalyst was traced using gas chromatography analysis. Solketal formation analysis using gas chromatography was used in this study. According to the results of gas chromatography analysis, the solketal produced without going through the distillation process has a purity of 23.54%, while the solketal produced after going through the distillation process has a purity of 38.94% when compared to the synthetic solketal produced by Sigma Aldrich, which has a purity of 95.67%. To manufacture solketal with a higher level of purity, the batch method was improved by adding a distillation process step to remove the water content and acetone that was still present in the sample.
Analysis of Students' Learning Difficulties in Physical Chemistry: Perspective on Various Sub-Variable Munawwarah Munawwarah; Sumiati Side
Jurnal Akademika Kimia Vol. 11 No. 4 (2022)
Publisher : Universitas Tadulako

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Abstract

This study aims to identify student learning difficulties in physical chemistry lectures. The subjects are 61 students in the chemistry education study program from two different classes. The research method used is mixed. Data were obtained by using instruments in the form of structured and unstructured questionnaires. Based on the results of the data analysis, several student learning difficulties were identified. Based on unstructured questionnaires, students' learning difficulties in physical chemistry material based on internal factors are caused because students find it difficult to do calculation problems, formulate derivation, and use many formulas. Based on external factors, namely the learning method used. Students prefer learning that is carried out face-to-face in a class by doing a lot of practice questions connected with applying formulas to questions and in everyday life. 55.7% of students in the medium category in learning disorder, 72% of students in the high category in learning disability, 65.5% of students in the medium category in learning dysfunction, 57% of students in the medium category in slowly learner, and 54% of students in the medium category in lower achiever. According to many students, physical chemistry is difficult. In addition, some of the causes of physical chemistry being considered difficult are confusion in analyzing questions, and learning conducted online during the Covid-19 pandemic is considered less effective. Students expect the learning method used to provide many examples and practice questions.
Activation of Durian Skin Biomass with H2SO4 Activator on the Absorption of Lead from its Solution Said, Irwan; Riski, Fahrul; Afadil, Afadil; Ningsih, Purnama
Jurnal Akademika Kimia Vol. 12 No. 1 (2023)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2023.v12.i1.pp44-51

Abstract

Research has been carried out on the bioabsorption of lead (Pb) using durian skin biomass (Durio zibethinus) which has been activated using an H2SO4 activator. The durian skin sample used was durian skin from Central Sulawesi. The processing technique to remove lead (Pb) from liquid waste was carried out by an adsorption process. The adsorption process is an effective purification and separation technique used in industry because it is more economical and simple in treating wastewater and is a technique that is often used to reduce metal ions in wastewater. This study aims to determine the mass and contact time of the adsorption of Pb by durian skin biomass. Determination of the adsorbed metal used atomic absorption spectrophotometry (AAS). The results obtained showed that the optimal Pb ion adsorption occurred at a weight of 2.5 grams with an absorption capacity of 99.94 %. While the optimal Pb ion adsorption occurred at a contact time of 40 minutes with an absorption capacity of 99.94 %.
Enhancement Mechanical Properties of Simalambuo Wood (Loppophetalum spp) Delignified using NaOH in The Thermomechanical Densification Method Nur Azizah; Febri Sindika; Andriayani Andriayani; Saharman Gea
Jurnal Akademika Kimia Vol. 11 No. 4 (2022)
Publisher : Universitas Tadulako

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Abstract

One of the problems with fast-growing wood is the low density, which causes poor mechanical properties, so a densification process is carried out to increase the wood's density, surface hardness, and strength. In this study, the delignification process using NaOH was carried out at variations of 12.24, and 48 hours and then continued with the thermomechanical densification process. This study decreased lignin content in delignification simalambuo wood from 30% to 4%. The value of the Modulus of Rupture, Modulus of elasticity, and surface hardness increases with increasing immersion time during the delignification process. The highest values of Modulus of Rupture, Modulus of elasticity, and surface hardness were obtained by simalambuo wood soaked for 48 hours, namely, 2828.23 kg/cm2, 97.47 kg/cm2, and 256.73 kg/cm2.
Development of Mouthwash Formulations based on Natural Ingredients with Antimicrobial Activity Adelia Y. P. Hasibuan; Harry Agusnar; Muhammad Taufik
Jurnal Akademika Kimia Vol. 11 No. 4 (2022)
Publisher : Universitas Tadulako

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Abstract

Dental and oral health problems are one of the problems that need attention. The oral cavity is colonized by various microflora and some bacteria, so it is necessary to develop additional oral cleaning methods besides brushing teeth. Mouthwash with natural ingredients, such as a combination of chitosan and Eucalyptus grandis, is the right choice. Chitosan is a type of water-soluble chitosan characterized using FT-IR. Meanwhile, Eucalyptus grandis was isolated using the Stahl method to obtain its essential oil. Mouthwash was evaluated through organoleptic testing, pH, viscosity, and antimicrobial testing. The most optimal formula is formula III, with an inhibition zone diameter of 11.9 ± 1.5 mm for Streptococcus mutans bacteria, 12.8 ± 0.9 mm for Staphylococcus aureus, and 12.2 ± 0.15 mm for Candida albicans.
The Potential of Crude Extract Bromelain Enzyme on Production of Virgin Candlenut Oil (VCdO) Sahfitri W. Nasution; Firman Sebayang; Juliati B. Tarigan
Jurnal Akademika Kimia Vol. 11 No. 4 (2022)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2022.v11.i4.pp253-260

Abstract

Virgin Candlenut Oil (VCdO) is carried out enzymatically without using high-temperature heating and does not use organic solvents so it produces an oil with good quality and low FFA levels. Bromelain enzyme is sourced from pineapple hump. This study aims to determine the optimal conditions of the characteristics of VCdO including yield and free fatty acid (FFA) levels. Analysis of the fatty acid composition of VCdO was characterized by Gas Chromatography (GC). The manufacture of VCdO was carried out using 3 parameters, namely variations in time, temperature, and the amount of catalyst (enzyme). Optimization of the yield and FFA levels was determined by the response surface method (RSM) based on the Box-Behnken experimental design with 3 factors and carried out as many as 15 experiments. The optimum yield of VCdO was 51.12% at 37 ℃, 34 hours, and enzyme volume 28 mL. The lowest level of FFA VCdO was obtained at 1.213% at 37 ℃, 12 hours, and enzyme volume 23 mL. The results of VCdO analysis with GC showed that the highest fatty acid content was linoleic acid at 43.73%. The FFA levels have obtained the quality standard of candlenut oil according to SNI 01 -4462 -1998.
Effect of Variation of Moringa Leaf Extract (Moringa oleifera L.) on Antioxidant Activity of Edible Film CMC/Chitosan Rezky A. Zainuddin; Basuki Wirjosentono; Cut F. Zuhra
Jurnal Akademika Kimia Vol. 11 No. 4 (2022)
Publisher : Universitas Tadulako

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Abstract

The edible film is an alternative to using synthetic polymer products because it is non-toxic, biodegradable, increases food safety, and extends food shelf life. The purpose of this study was to see how the effect of adding Moringa leaf extract on the antioxidant activity of CMC/Chitosan edible film. This study consisted of two stages, the first stage was extracting Moringa leaves using ethanol, and the second stage was making edible film CMC/chitosan with the addition of variations of Moringa leaf extract (0.5%, 1%, 1.5%, and 2%). The results of the antioxidant activity test showed that the edible film with the best variation was EE with an IC50 value of 4.45 ppm which was categorized as very strong and physical properties such as absorption, solubility, and water vapor transmission were 72.19%, 92.04%, and 6.21 g/m2h.
Comparison of the Composition of Cinnamomum verum J. Presl and Zingiber officinale Roscoe to the IC50 Value Aries K. Sundoro; Etty Sulistyowati
Jurnal Akademika Kimia Vol. 11 No. 4 (2022)
Publisher : Universitas Tadulako

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Abstract

Antioxidants are substances that can reduce and prevent free radical damage or prevent oxidative damage. The combination of two or more plant species can result in a greater potential for antioxidant activity. The purpose of this study was to determine the IC50 value of the combination of Cinnamomum verum J. Presl and Zingiber officinale Roscoe with a ratio of 1:2, 1:1, and 2:1. Antioxidant activity was determined by the amount of DPPH absorption inhibition (% Inhibition) and the value (50% Inhibition Concentration). The IC50 value in antioxidant activity measurement of ethanol extract combination of Cinnamomum verum J. Presl and Zingiber officinale Roscoe in the ratio of 1:2, 1:1, and 2:1, was 372.3078 ppm, 354,3077 ppm, and 344.0863 ppm respectively. The ethanol extract of Cinnamomum verum J. Presl and Zingiber officinale Roscoe at a ratio of 2:1 was the best combination with total phenolic content of 5.63 mgGAE/100 g and produced an IC50 value of 344.0863 ppm.

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