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Daud K. Walanda
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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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Antioxidant Activity Test of Ethanol Extract of Ripe and Young Cocoa Pods (Theobroma Cacao L.) Andriana Andriana; Minarni R. Jura
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.pp64-71

Abstract

Antioxidant activity test of Ethanol Extract of Ripe and Young Cocoa Pod Skin (Theobroma Cacao L.) with DPPH (1,1-diphenyl-2-picrylhydrazyl) using UV-Vis spectrophotometer has been carried out. This study aimed to determine the IC50 value of the ethanol extract of ripe cocoa pods and young cocoa pods (Theobroma Cacao L.). The mature and young cocoa pods were extracted using absolute ethanol solvent and tested for their antioxidant activity using DPPH (1,1-diphenyl-2-picrylhydrazyl). The concentration variations used in the ethanol extract of ripe cocoa pods and young cocoa (Theobroma Cacao L.) were 20 ppm, 40 ppm, 60 ppm, and 80 ppm. The results showed that the IC50 values of the ethanol extract of ripe and young cocoa pods were 76.094 ppm and 91.884 ppm, respectively. Meanwhile, the IC50 value of vitamin C compared was 63.519 ppm. Based on the IC50 value data above, it can be seen that the antioxidant activity of the ethanol extract of young cocoa pods and ripe cocoa pods are potent antioxidants.
Study of Conceptual Change in Chemistry for Class XI Science High School Students Hartarti Uminah; Ijirana Ijirana; Siti Nuryanti
Jurnal Akademika Kimia Vol. 11 No. 2 (2022)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2022.v11.i2.pp77-82

Abstract

Varied initial concepts can be an obstacle or support in understanding a new concept. The study of changes in students' chemical concepts was carried out on thermochemical material. This study aimed to examine changes in students' thermochemical concepts in each subject of high, medium, and low ability. Qualitative descriptive research with mixed methods was conducted on SMAN 1 Bumi Raya Morowali, Central Sulawesi students. The study began by giving an initial test to all students of class XI IPA 1 and 2, as many as 60 students, to obtain initial concept data and the basis for grouping subjects on each ability criterion (high, medium, and low). Every two people from each ability group in semi-structured interviews. Thermochemical material is re-taught using a metacognitive skill learning model and given a final test and interview to get concept data after learning to assess conceptual changes. Five concepts become variables in this study: the heat of reaction, enthalpy of reaction in a calorimeter, Hess's law, energy diagrams, and bond energies. The results showed that concept changes occurred in all high, medium, and low ability subjects. Changes in students' conceptions occurred in the concepts of the heat of reaction, reaction enthalpy, calorimeter, Hess's law, energy diagrams, and bond energy. The most significant conceptual change occurred in the subject of medium ability and low ability, namely the concept of bond energy.
The Extraction of Nickel from Morowali Laterite Ore with Nitric Acid I W. A. Wirawan; Daud K. Walanda; Mery Napitupulu
Jurnal Akademika Kimia Vol. 11 No. 2 (2022)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2022.v11.i2.pp91-95

Abstract

Nickel extraction from Morowali laterite ore has been carried out with nitric acid as the solvent. This study aims to determine the effect of nitric acid concentration, temperature, and stirring time on nickel content in laterite ore originating from Morowali. Morowali laterite seeds were extracted using the leaching method using nitric acid as the solvent with various concentrations of 0.5, 1, and 2, temperatures of 30, 60, and 95, and stirring times of 3, 6, and 12. Taguchi analysis was used in this study to obtain the effect of the three parameters used. The results showed that the optimum conditions were obtained at a concentration of 2 molars nitric acid, a temperature of 95°C, and a stirring time of 12 hours, with a nickel content of 16.469 ppm and a nickel recovery percent of 3.88%.
Phospate Release Study on Silica Gel and Amino Silica Hybrid Sorbent from Lapindo Mud Ade I. Agipa; Muhamad F. Muarif
Jurnal Akademika Kimia Vol. 11 No. 2 (2022)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2022.v11.i2.pp83-90

Abstract

This study discusses the rate of phosphate release in Silica Gel (SG) and Amino Silica Hybrid (ASH) sorbents using Lagergren pseudo-first Order Kinetic and Lagergren Pseudo-second Order Kinetic. ASH synthesis was done by adding a 3-aminopropyltriethoxysilane (APTES) modifier to sodium silicate from Lapindo Mud. Phosphate binding was carried out at 30 minutes with a stirring speed of 250 rpm. Analysis using IR spectrophotometer showed the success of ASH synthesis as indicated by the appearance of functional groups -NH2 and -CH2 at wavenumbers 1635 cm-1 and 1473 cm-1. With the continuous method, SG and ASH sorbents that have bound phosphate were then desorbed at various times of 2, 3, 4, 7, 8, and 9 days. The amount of phosphate anion released from SG and ASH was tested using a UV-Vis instrument then modeling was carried out to determine the rate of phosphate release. The desorption results showed the amount of phosphate released from the ASH sorbent was less than that of the SG sorbent. Through modeling, the proceeds of the phosphate release rate follow the Lagergren Pseudo-second Order Kinetic with an experimental QE of 0.22089 M/g for SG sorbent and 0.33333 M/g for ASH sorbent.
Equilibrium and Adsorption Kinetic Study of Metal Ni(II) using Persimmon Tannin Gel La O. Ahmad; Ulfa H. Syam; Laode A. Kadir; Nohong Nohong; Muh Natsir; Nasriadi Dali; Imran Imran; Tahril Tahril; Thamrin Azis
Jurnal Akademika Kimia Vol. 11 No. 2 (2022)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2022.v11.i2.pp111-116

Abstract

Heavy metal concentration exceeding the threshold amount is hazardous to the environment, so it needs some treatment. The study aimed to know the capacity and kinetics of adsorption. This study used the adsorption method to remove the heavy metal ion Ni(II) using persimmon tannin gel. Influences of time contact, pH, and ion concentration in the adsorption process were also investigated. Results showed optimum adsorption at 60 minutes of time contact and pH 5. Variation of concentration made the adsorption decrease as metal ion Ni(II) concentration increased. The maximum adsorption capacity was 23.14 mg/g by using pseudo-second-order adsorption kinetic model.
Analysis of Water Quality and Pollution Index at Karangantu Fishing Port Area, Banten Roza Ruspita; Atika Aulia
Jurnal Akademika Kimia Vol. 11 No. 2 (2022)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2022.v11.i2.pp96-104

Abstract

Karangantu fishing port symbolizes the rapid fishing industry in Serang, Banten. So many activities in the Karangantu fishing port area, such as a place for landing fisherman’s boats, shipping fish catches, and tourism object. These activities may impact the water quality. This research aims to analyze the water quality and pollution index in Karangantu fishing port. The water sample was carried out by purposive sampling in three stations around the Karangantu fishing port area: the estuary area, the fish auction, and the dock. Twelve parameters were analyzed: temperature, turbidity, transparency, TDS, TSS, pH, DO, COD, nitrate, cadmium, lead, and total coliforms. The water quality analysis result was compared by Class III water classification based on PP RI Nomor 82. Water quality was determined by the pollution index based on the minister of environment decree No. 115/2003. The result indicates that the estuary area is polluted, with a PIj score of 6.35; the fish auction and the dock f are in the moderately polluted categories, with PIj scores of 4.99 and 3.90. The worse pollution can be prevented by raising public awareness about the importance of clean water and providing waste management facilities.
Calcium Extract Characterization from Rajungan Crab Shell (Portunus pelagicus) and Bakau Crab Shell (Scylla serrata) using Calcination as Effervescent Mohammad R. Usman; Muhamad D. Permana; Aditya F. Ardinsyah; Mega T. Wulandari; Aliyah Purwanti; Lindawati Setyaningrum; Ima F. Lestari; Stephanie D. Artemisia
Jurnal Akademika Kimia Vol. 11 No. 2 (2022)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2022.v11.i2.pp122-128

Abstract

One of the prevention of osteoporosis is by taking calcium supplements. Crab shells are calcium sources that can be processed into supplements. Calcium extraction used the calcinations method at 900°C temperature for 4 hours. After calcining the crab shell powder, it was analyzed by using XRD and processed with the Highscore Plus application by using Rietveld method. The best calcium crystals will be used as raw material for effervescent powder. The results showed that calcium crystals from rajungan crab shells contained 0.4% CaCO3 with a crystallite size of 25.9001 nm and 99.6% CaO with a crystallite size of 82.7183 nm with a GoF value of 1.69979. Calcium crystals produced from bakau crab shells were 100% CaO with a crystallite size of 77.3397 nm with a GoF value of 1.90266. Calcium crystals from bakau crab shells were used as effervescent raw materials with 2 different formulations. The results of the organoleptic test from both effervescents showed the same results, namely in the form of a pale yellow powder with a orange scent and sour taste The results of the dispersion time test showed that the 2 formulations had met the requirements with the dispersion time of formula 1 being 31.67 seconds and formula 2 being 32.33 seconds. The results of the water content test of the two formulas met the requirements with the water content of formula 1 being 0.071% and formula 2 being 0.067%.
The Use of Augmented Reality Based-Learning Media to Reduce Students' Misconceptions Frelyana Tiro; Afadil Afadil
Jurnal Akademika Kimia Vol. 11 No. 3 (2022)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2022.v11.i3.pp140-145

Abstract

The research objective is to determine whether using AR molecules as a learning medium can assist students in reducing their misconceptions about molecular materials. It was pre-experimental research with a one-group pre-test-post-test design. The average level of validity of the learning media used, according to the findings, is 70.3% ("valid" classification). The average reduction of misconceptions (MC) among students using learning media for the entire concept is 12.8 %, 9.2 % for students who do not understand the concept (DUC), and 22.0 % for students who understand the concept (UC). Based on these findings, it is possible to conclude that AR molecule-based learning media can be used to reduce students' misconceptions about molecular materials.
Extraction of Nickel from Morowali Laterite Ore with Hydrochloric Acid (HCl) I Komang Jati Purnawan; Daud K. Walanda; Mery Napitupulu
Jurnal Akademika Kimia Vol. 11 No. 3 (2022)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2022.v11.i3.pp134-139

Abstract

This study aims to determine the influence of temperature, leaching time, and the influence of hydrochloric acid concentration in the nickel extraction process, as well as to determine the optimum conditions of the laterite nickel extraction process using the Taguchi method which is influenced by hydrochloric acid concentration, temperature and leaching time. The laterite samples used came from the Bahodopi District, Morowali Regency, Central Sulawesi Province. Quantitative analysis using AAS (Atomic Absorption Spectrophotometer) with variables studied including acid concentrations of 0.5 M, 1 M, and 2 M, temperatures with levels of 30oC, 60oC, and 95oC, and leaching times of 3 hours, 6 hours, and 12 hours. The optimum conditions obtained from the results of the study were at a temperature of 95oC, a leaching time of 12 hours and a concentration of 2 M with the optimum absorbance obtained, namely 0.1635, the optimum concentration of 5.9693 mg /L with a percent of nickel recovery obtained of 1.41%.
The Influence of Problem-Based Learning Model Learning Assisted by Science Media Kits on Student Learning Outcomes in Hydrocarbons Ulfiana Ulfiana; Minarni R. Jura; Tahril Tahril
Jurnal Akademika Kimia Vol. 11 No. 2 (2022)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2022.v11.i2.pp105-110

Abstract

This study aimed to determine the effect of the problem-based learning model assisted by KIT IPA media on student learning outcomes in hydrocarbon material in class XI IPA SMA N 6 Palu. The type of research used was Pre-experiment with Alternative Treatment design, Post-Test-Only with nonequivalent Groups Design. Sampling was done using the purposive sampling technique with samples consisting of class XI IPA 4 as experimental class I and class XI IPA 2 as experimental class II. The research instruments were the learning outcomes tests, RPP, and observation sheets previously validated in theory and empirically. Testing student learning outcomes used t-test analysis two (two parties) with a prerequisite test: normality and homogeneity tests, then the t-test hypothesis test (two parties) was applied. Based on the research results and analysis of the research data, the value of student learning outcomes in the post-test of the experimental class I was 65.7 and for the exploratory class II was 59.9, while the standard deviation was 10.4 and 9.7, respectively. The results of the statistical testing of hypothesis testing obtained tcount> ttable or 2.60> 1.70 so that H1 was accepted. It means that the learning model of problem-based learning instruction assisted by KIT IPA media affects the learning outcomes of students of SMA Negeri 6 Palu.

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