Jurnal Akademika Kimia
Not a member yet
213 research outputs found
Sort by
Extraction of Nickel from Morowali Laterite Ore with Hydrochloric Acid (HCl)
Get PDFThis 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%
Effect of Variation of Moringa Leaf Extract (Moringa oleifera L.) on Antioxidant Activity of Edible Film CMC/Chitosan
Get PDFThe 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
Development of Chemistry’s Learning Module Oriented Local Wisdom of Central Sulawesi for High School in Basic Acid Solution Materials
Get PDFDevelopment research has been carried out to produce a high school chemistry learning module that oriented Central Sulawesi’s local wisdom in acid-base solutions. This research was conducted using research and development (R&D) methods. The goal of this study was to ascertain the validity and applicability of the developed learning modules. Development of the learning module is expected to be used by teachers as users and for students in their independent learning, increasing the understanding of concepts and getting to know local wisdom in the Central Sulawesi region. The validity of the learning module was determined by a validation test conducted by specialists in the topic, medium, and user. In contrast, the practicality of the learning module was determined by the outcomes of the module's implementation by students. The validation results showed that the average score of the material expert of 2,66 was categorized as “valid,” the average score of the media expert was 3,29 with the category “valid,” and the average score of the user was 3,53 with the category “valid.” The results implementation of learning modules using students' response questionnaires obtained respectively, a percentage of 29% of students responded was “very practical,” 64,4% of students responded war “practical,” 6% of students responded was “impractical,” and 0% of students respond was “very impractical.” Based on these results, it can be concluded that the development module was “valid” and “practical” in using the learning process
Flavonoid Compounds of the Catechin from Wungu (Graptophyllum pictum (L.) Griff) Leaves and the Sun Protecting Factor Value
Get PDFThe 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 protectio
The Influence of Problem-Based Learning Model Learning Assisted by Science Media Kits on Student Learning Outcomes in Hydrocarbons
Get PDFThis 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
The Processing of Glycerol with Acetone to Produce Solketal Using Amberlite IR 120 Na Catalyst: Comparison of solketal Production Using Gas Chromatography
Get PDFSolketal 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
Comparison of High School Student’s Learning Outcomes Using Cooperative Learning Model Between Think-Pair-Share (TPS) and Teams Games Tournament (TGT) Types on Reaction Equation
Get PDFThis study aimed to describe the difference between students’ learning outcomes from the class using the cooperative learning model of think pair share (TPS) type and teams games tournament (TGT) type on the topic of reaction equation in class X at MAN 2 Model Palu. This study was a pre-experiment with the static group pretest-postest design. This study was conducted in two groups i.e., class XA as experiment group 1 (n = 24) and Class XB as experiment group 2 (n = 23). Data of students’ learning outcomes were analyzed using t-test two-party statistical analysis with the prerequisite of normality and homogeneity tests of the data from the given posttest. The analysis results obtained the average score of experimental class 1 (1X) was 68.25, while the average score of the control class (2X) was 63.15. The hypothesis test results obtained tcount = 2.47 and ttable = 2.02 with significance level = 0.05 and degrees of freedom 45, then H0 was rejected, and Ha was accepted. Based on these results, it can be concluded that students’ learning outcomes from the class using the cooperative learning model of think pair share (TPS) type is different from the class using cooperative learning model of teams games tournament (TGT) type on the topic of reaction equation in the Class X at MAN 2 Model Palu. Students' learning outcomes in experimental class 1 were higher than in experimental class 2
Analysis of Flavonoid Levels in Tin (Ficus carica Linn) Fruit
Get PDFTin fruit is an essential source of bioactive components such as phenol, benzaldehyde, and flavonoids due to the antioxidant properties. Analysis of flavonoid levels on Tin (Ficus carica Linn) fruit was carried out using Uv-Vis spectrophotometry. This study aimed to determine the total flavonoid levels found in Tin (Ficus carica Linn) fruit with a variety of samples of raw, half-ripe, and riped. Extraction of chemical content in Tin (Ficus carica Linn) was carried out by maceration method with ethanol 70%. Total flavonoid levels of the extracts sample were determined through absorption measurements at a wavelength of 520 nm and 700 nm. The results showed that total flavonoid levels in raw, half-ripe, and ripe fruits are 5.778 × 103, 3.056 × 103, and 3.707 × 103 mg/L, respectively, or equivalent to 17334 × 103, 9.168 × 103, and 11.121 × 103 mg/100g, respectively
The Implementation of SAVI (Somatic, Auditory, Visual, and Intellectual) Learning Model toward Critical Thinking Ability of Students in Grade XI on the Subjects of Solubility and Solubility Product Constant (Ksp)
Get PDFThis study aimed to determine students' critical thinking ability through the implementation of SAVI (somatic, auditory, visual, and intellectual) learning model on the subject of solubility and solubility product constant (Ksp) at SMA Negeri 5 Model Palu. The study used one group pretest-posttest design. The instruments were lesson plans, critical thinking tests, students' worksheets, and validated observation sheets. Data of critical thinking abilities were analyzed using rubrics with three indicators, i.e. interpretation, analysis, and inference. Results of data analysis on students' critical thinking skills at the pretest on each indicators in Experiment class I were 25.84, 11.13, and 2.44%, respectively; while in class II were 23.51, 1.38, and 0%, respectively. The posttest in Experiment class I were 69.94, 61.13, and 53.51%, respectively, while in class II were 79.55, 48.61, and 49.07%, respectively. The average of students' critical thinking skills ability in experiment class I was 61.02%, and class II was 61.47%. Both of them were in the moderate category. This study concludes that students' critical thinking skills ability with the implementation of SAVI learning model is in a good category. The average of students' critical thinking skills ability in experiment class I was 61.02%, and in experiment class II is 61.47%. Both of them were in the moderate critical thinking category. This study concludes that students' critical thinking skills ability with the implementation of SAVI learning model is in a good category
Analysis of Student Misconceptions on the Problem Based Learning (PBL) Model Assisted with Interactive Multimedia on Acid Basic Solutions
Get PDFThis 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%