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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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Implementation of Guided Inquiry Learning Model on Colloid Systems to Improve Critical Thinking Ability of Students Nurul R. Arini; Sri M. Sabang; Anang W. M. Diah
Jurnal Akademika Kimia Vol. 10 No. 2 (2021)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2021.v10.i2.pp87-92

Abstract

Critical thinking is the ability to solve problems through an investigation so as to produce conclusions or rational decisions. This study aimed to obtain an improvement of critical thinking skills of students in Grade XI at SMAN 3 Palu after the implementation of the guided inquiry learning model on Colloid Systems. This study was a pre-experiment with one group pretest-posttest design. The sample was run by simple random sampling with the sample of Class XI Science 1 as the replication class 1 (n = 36) and Class XI Science 3 as the replication class 2 (n = 35). Data on students' critical thinking was taken using tests that were given before and after learning. An improvement in students' critical thinking skills in replication class 1 and replication class 2 was by 50%. Data of students' critical thinking skills were tested using non-parametric statistical analysis, namely the Mann-Whitney test. The test results obtained the Zh value -0.076, so -1.96 ≤ -0.076 ≤ +1.96. This result is in the reception area of Ho, and H1 is rejected. It means that the average score of critical thinking ability of students in the replication class 1 is the same as in replication class 2. This study concluded that the implementation of the guided inquiry learning model on Colloid Systems improves the critical thinking skills of students in Grade XI at SMAN 3 Palu.
Conceptual Changes of Students in Thermodynamics in Physical Chemistry Course Through The Implementation of Blended Learning Afadil Afadil; Sitti Rahmawati; Suherman Suherman
Jurnal Akademika Kimia Vol. 10 No. 3 (2021)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2021.v10.i3.pp174-181

Abstract

This study aims to determine the conceptual changes of students after participating in learning with a blended learning approach on Thermodynamics material. This research is a type of pre-experimental (pre-experimental design) with a One Group Pretest-Postest Design. The blended learning approach is applied using the Problem Based Learning model. The research sample was Class C Odd Semester 2019/2020 students which consisted of 34 students who programmed Physical Chemistry courses. The instrument used is a two-tier multiple choice test which includes concepts in Thermodynamics material which is equipped with a valid CRI. The blended learning approach is one approach that can be used that facilitates student activities in utilizing ICT through the delivery of materials, discussion of task completion, and training in the search for teaching materials on Thermodynamics material. The results showed that misconceptions still occur in every concept of Thermodynamics. The average reduction of misconceptions (MC) is 11.2%, the increase in the number of students to knowing concept (KC) classically is 19.2%, and the decrease in the number of students unknowing concept (UKC) is classically 8.1%. Students' conceptual changes to the material of Thermodynamics are still low. Students are required to understand well the content of the material related to basic concepts, mathematical equations (formulas), and the applicative forms of concepts in everyday life in accordance with the characteristics of the thermodynamic material.
Development of Hollow Fiber Liquid Phase Microextraction Method for Determination of Diazinon Residues in Vegetable Samples Eviomitta R. Amanda; Yanuardi Raharjo; Usreg S. Handajani
Jurnal Akademika Kimia Vol. 11 No. 1 (2022)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2022.v11.i1.pp6-13

Abstract

An extraction method based on a combination of hollow fiber liquid-phase microextraction with high-performance liquid chromatography diode array detector (HF-LPME HPLC-DAD) has been developed and demonstrated to analyze pesticide residues in vegetables. This study aims to determine the optimum extraction conditions and validation performance of this method. Diazinon pesticide was selected as the target model analyte. HF-LPME is performed by stacking microliter organic solvent droplets through an HPLC syringe coated with polypropylene hollow fiber by directly dipping it into the sample solution and stirring it during the extraction process. Finally, the organic solvent was put into an HPLC syringe at the end of the extraction. Then, it was injected into the HPLC-DAD at the wavelength of 247 nm. Several important extraction parameters have been optimized. The optimization results showed the type of organic solvent of n-hexane, the length of the hollow fiber of 1.5 cm, the volume of the sample solution of 20 mL, and the stirring speed of 600 rpm. The validation performance obtained a limit of detection (LoD) of 0.10 mgL-1, limit of quantification (LoQ) of 0.33 mgL-1, percent recoveries of 99.88%, a coefficient of variation of 3% (n=15), and the enrichment factor of 19,982 times. Under optimal conditions, the developed method was applied to extract diazinon in vegetable matrix samples using the spiking method. Mustard green was selected as a model matrix sample. From the research, the percentage recoveries of diazinon obtained in the mustard green matrix sample are 98.80% - 100.41%.
Flavonoid Compounds of the Catechin from Wungu (Graptophyllum pictum (L.) Griff) Leaves and the Sun Protecting Factor Value Masyita Masyita; Endah Sayekti; Nurlina Nurlina
Jurnal Akademika Kimia Vol. 11 No. 1 (2022)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2022.v11.i1.pp31-38

Abstract

The flavonoid content in wungu (Graptophyllum pictum (L.) Griff.) leaves has the potential as a sunscreen. The study aims to identify isolates of flavonoid compounds from wungu leaves and determine the SPF value. Steps are followed by extraction, fractionation, phytochemical test, separation by chromatography, identification, and SPF test. Extraction was carried out with methanol, followed by fractionation with n-hexane and dichloromethane. Dichloromethane fraction was chosen to proceed to the separation step because the results of the phytochemical test showed a vigorous color intensity for the content of flavonoids. The isolate (3.6 mg; dark green; amorphous; mp. 132-136 °C) was identified using a UV-Vis spectrophotometer using methanol as a solvent with a shift reagent NaOH, AlCl3, and a mixture of concentrated AlCl3 and HCl. Based on the UV-Vis spectra, the isolate was predicted to be flavonoid compounds belonging to the catechin group, which have a hydroxyl group at positions C-3, C-7, and do not have an ortho-hydroxy group in ring B. The SPF value of the isolate of 2.3244 at 100 ppm was determined in vitro and calculated by the Qian equation. Therefore, isolate was categorized as sunscreens that provided minimal protection
Concentration Effect of Watermelon Skin Extracts (Albedo) as Organic Inhibitors on the Corrosion of Iron Nails in 3% NaCl Medium Solution Nurhikmah Nurhikmah; Minarni R. Jura
Jurnal Akademika Kimia Vol. 10 No. 3 (2021)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2021.v10.i3.pp153-158

Abstract

This study aimed to determine the concentration effect of skin extract in watermelon on the inhibition of corrosion rates of iron nails in the corrosive medium of NaCl solution and seawater as a comparison. The study began with the first maceration of the skin in watermelon and then followed by evaporation to produce extracts specific gravity 0,097 gram/mL as inhibitors with variations in concentrations of 1, 2, 4, 8, and 16%. The method of determining the corrosion rate used was the weight loss method from the 7-day immersion process. The results showed that the greatest corrosion inhibition efficiency occurred at a concentration of 8% for immersion with 3% NaCl corrosive medium and 4% concentration for immersion in seawater with the efficiency of 11.56% and 22.15%, respectively. Based on the results of the study, it was found that each addition of extract in watermelon can affect the effectiveness of inhibition.
Analysis Redox Reaction on Zinc-Coating Thickness Test in Metal Processing Industry of Small and Medium Enterprises Gatot Triyanto; Ricky R. Saputro; Chepi Reynaldir; Khoirudin Khoirudin; Sukarman Sukarman
Jurnal Akademika Kimia Vol. 11 No. 1 (2022)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2022.v11.i1.pp19-25

Abstract

This study discusses the implementation of redox reactions on the thickness test of the galvanized (zinc-coated) layer using the JIS-H-0401 standard to help Small and Medium Enterprises (SMEs) industries. Some of the finished products go through the galvanizing process in the metal processing industry. Quality constraints, especially related to the thickness of the galvanic (zinc-coated) layer, have become an object that is less controlled because of the limitations of the test equipment used. This research uses an experimental method applied to one of its products: a flat washer with SPCC material and a thickness of about 2.20 mm. SPCC - SD material is classified as low carbon steel based on its carbon content. 5-unit flat washers were identified with sample codes A, B, C, D, and E. Flat washers have an internal diameter of 22.65 - 22.7 mm. In comparison, the outer diameter is between 43.75 - 43.80. The redox reaction process uses HCl (hydrochloric acid) with a concentration of 1 M, which is diluted with water (H2O). The zinc thickness test results show that the flat washer has an average thickness of 10.52 microns with a minimum and maximum thickness variation of 10.66 -10.72 microns.
The Effect of Surfactants on Separation of Light Rare Earth Metals using Emulsion Liquid Membrane Method: Review Dwi Ratna Setiani; Afifah R. Widianti; Fauzia Salsabila; Anni Anggraeni; Husein H. Bahti; Uji Pratomo
Jurnal Akademika Kimia Vol. 11 No. 1 (2022)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2022.v11.i1.pp46-55

Abstract

Rare earth metals (REM) are scarce elements and are only found in the form of complex compounds of phosphate and carbonate. REM consists of 17 elements classified into light REM, medium REM, and heavy REM. This article is focused on lightweight REM, which is widely applied in various industrial fields. Many REM applications are increasing the demand for high-purity and bulk REMs. However, REM has almost the same physical and chemical properties, making it difficult to separate. Therefore, the separation of REM is interesting to study with various methods, one of which is Emulsion Liquid Membrane (ELM). ELM is developing a solvent extraction method involving three phases: the external phase, the internal phase, and the membrane phase. The key to the success of ELM lies in the stability of the emulsion, which is very dependent on the type and concentration of surfactants, so in the ELM process, it is necessary to choose the right concentration and type of surfactant. Therefore, this article was made to know the effect of surfactants such as span-80, span-85, and T154 in separating light REM using the ELM method.
Preliminary Study of Chemistry Knowledge Through Ethnochemistry Approaches to Communities Ade P. Maedja; Purnama Ningsih
Jurnal Akademika Kimia Vol. 10 No. 3 (2021)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2021.v10.i3.pp188-194

Abstract

This research was a descriptive qualitative study using ethnographic methods. It aimed to determine the understanding and application of chemistry knowledge in the daily lives of Wiapore society, Marawola Barat district, through an ethnochemistry approach. Data obtained was in the form of an initial data inventory. These inventory data were then grouped into several data categories, namely categories related to food, beverage, and agriculture categories. The percentage value of each data was as follows, related to food 55.55%, related to drinks were 22.22%, and connected to agriculture were 22.22%. The results of this study are significant for local governments in taking policies relating to education for children and the Wiapore community
Analysis of Student Misconceptions on the Problem Based Learning (PBL) Model Assisted with Interactive Multimedia on Acid Basic Solutions Fitriani Mandasari; Irwan Said
Jurnal Akademika Kimia Vol. 10 No. 3 (2021)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2021.v10.i3.pp195-202

Abstract

This study aimed to analyze students' misconceptions on Acid-Base Solution after applying the Problem Based Learning (PBL) model assisted with interactive multimedia in grade XI at SMA 4 Palu. This type of research was a quantitative descriptive study with a total sample of 1 class, namely class XI Science-2, with 33 students. The research instrument used was a reasoned multiple-choice test accompanied by a Certainty of Response Index (CRI) consisting of 15 items. The results obtained the average percentage of students' misconceptions in Problem Based Learning (PBL) assisted with interactive multimedia in Acid-Base Solutions before and after the successive application was 42.9% and 21.8%. Thus the application of the PBL model reduced student misconceptions by 21.1%.
Determination of Vitamin C and Metal Copper (Cu) Levels in Katokkon Chili (Capsicum chinense Jacq) Based on Maturity Level Novianti Patiung; Daud K. Walanda; Sitti Aminah
Jurnal Akademika Kimia Vol. 10 No. 3 (2021)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2021.v10.i3.pp182-187

Abstract

Katokkon chili is one type of chili grown mainly in the Tana Toraja district, and the people use this plant as a typical spice with variations colors from green, orange, and red. It is assumed that the plant is rich in vitamins and minerals. This study aims to determine the levels of vitamin C and copper metals in katokkon chili based on their level of maturity. Vitamin C and copper levels were determined by spectrophotometry. The results showed that the highest level of vitamin C was 23.52 and 5.12 mg/kg in both wet and dry orange chilies, while the highest copper level was found in green chili was 12.25 mg/kg

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