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Jurnal Akademika Kimia

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Published by Universitas Tadulako

ISSN : 23026030 EISSN : 24775185 DOI : https://doi.org/10.22487/

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 137 Documents

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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

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

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

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

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

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

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

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

Co-pigmentation of Anthocyanin Jamblang Fruit (Syzygium cumini) with Acetic Acid and Alum Chintia N. Barani; Siti Nuryanti; Paulus H. Abram
Jurnal Akademika Kimia Vol. 10 No. 4 (2021)
Publisher : Universitas Tadulako

This study aimed to determine the effect of temperature on the stability of anthocyanin jamblang after co-pigmentation with acetic acid and alum. The extraction of Jamblang fruit used the maceration method with n-hexane, ethyl acetate, and ethanol-HCl 0.5% solvents. The total anthocyanin obtained was 70.64 mg/L. Anthocyanin of jamblang fruit was co-pigmented with acetic acid and alum in a concentration of 2.5%; 5%; 7.5%; and 10%, then be heated at various temperatures and heating times. At a temperature of 80 ℃ for 150 minutes, every 30 minutes, absorbance was measured. At a temperature of 60 ℃, the heating was carried out for 225 minutes, and every 45 minutes, absorbance was measured. At a temperature of 40 ℃, the heating was carried out for 300 minutes, and every 60 minutes, absorbance was measured. Absorbance measurements were taken using a UV-VIS spectrophotometer. The results showed that co-pigmentation of anthocyanin occurred proved by shifting λ max from 470 nm (unco-pigmented extract) to 500 nm (co-pigmented extract acetic acid) and 540 nm (co-pigmented extract alum). Acetic acid and alum co-pigments maintained the stability of anthocyanin jamblang at a heating temperature of 60 ℃. It can be seen from decreased absorbance, which is not so significant compared to the decrease at temperatures of 40 and 80 ℃, accompanied by anthocyanin's fading color, which is co-pigmented with acetic acid and alum during the heating process.

Analysis of Students' Skills through Practicum on Reaction Rate Topic Hayatul Islam; Ratman Ratman
Jurnal Akademika Kimia Vol. 10 No. 4 (2021)
Publisher : Universitas Tadulako

National education emphasizes learning on assessing students' knowledge, attitudes, and skills. The development of skills aspect is not enough only relying on the learning in the classroom, but also necessary doing understanding outside the classroom such as practicum in the laboratory. The implementation of training allows students to practice their skills and help students understand the material taught in the class. This study aimed to describe the quality of students' skills on reaction rate topics through a practicum in grade XI at SMA Negeri 5 Palu. This type of research was a quantitative descriptive study with a one-shot case study design. Sampling was conducted by purposive sampling. The sample was Class XI Science 2 as the experimental class 1 with 23 students and Class XI Science 3 as the experimental class 2 with 25 students. The quality skill of students was measured by instruments in the form of observation sheets as the primary data. The data obtained through the observation sheet showed that the average percentage of all aspects of student skills in experimental class 1 was 74.81%, and in experimental class 2 was 74.05%. It indicates that the ten skills elements have emerged in the learning activities with a good category. This study concludes that the quality skill of grade XI students at SMA Negeri 5 Palu on learning reaction rate topic through practicum is a good category.

The Utilization of Acid as a Color Stabilizer in the Extraction of Anthocyanins from the Lakum (Cayratia trifolia L.) Peel Aryo E. Peluru; Paulus H. Abram
Jurnal Akademika Kimia Vol. 10 No. 4 (2021)
Publisher : Universitas Tadulako

Anthocyanins are a group of natural dyes (pigments) that give many colors to plants’ leaves, flowers, and fruits. Anthocyanins are generally acidic and more stable under acidic conditions. One of the plants that contain anthocyanin is the lakum (Cayratia trifolia L.) fruit ripe with a blackish-purple color. This study aimed to determine the best type of acid used to extract anthocyanins from the lakum fruit peel. The extraction process was carried out by maceration method using 96% ethanol solvent acidified with three types of acids, HCl 1%, citric acid 3%, and acetic acid 3%, with an average level of anthocyanin obtained of 283.88, 220.70, and 226.55 mg/L, respectively. This study indicated that the best acid used to extract anthocyanin from the lakum fruit peel with the highest total anthocyanin results was by adding HCl 1%.

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Daud K. Walanda

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jak.untad@gmail.com

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Program Studi Pendidikan Kimia-FKIP Universitas Tadulako Jl. Soekarno-Hatta Km.9, Palu-Indonesia 94119

Location
Kota palu,

Sulawesi tengah

INDONESIA

Abstract

Abstract

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Abstract

Abstract

Abstract

Home Page

OAI Link

Editorial Team

Contact

Reviewer

Google Scholar

Contact Name Daud K. Walanda

Contact Email walanda@gmail.com

Phone +6281245207927

Journal Mail Official jak.untad@gmail.com

Editorial Address Program Studi Pendidikan Kimia-FKIP Universitas Tadulako Jl. Soekarno-Hatta Km.9, Palu-Indonesia 94119

Location Kota palu, Sulawesi tengah INDONESIA

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Contact Name
Daud K. Walanda

Contact Email
walanda@gmail.com

Phone
+6281245207927

Journal Mail Official
jak.untad@gmail.com

Editorial Address
Program Studi Pendidikan Kimia-FKIP Universitas Tadulako Jl. Soekarno-Hatta Km.9, Palu-Indonesia 94119

Location
Kota palu,

Sulawesi tengah

INDONESIA