Jurnal Akademika Kimia
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Relevance and Consistency of Lithium Application Learning Media for High School Students on Chemical Equilibrium Material
Get PDFConditions of the Covid-19 pandemic require teachers and students to innovate starting from the preparation, process, and assessment of learning. This study aims to design and determine the relevance and consistency of Lithium application learning media for high school students on chemical equilibrium in the form of e-modules as a solution to reduce misconceptions. This type of research is a part of Research and Development (R&D) starting from product design to determining its theoretical relevance and consistency by experts. The product produced is in the form of an e-module on chemical balance material using Android with the Lithium application which is used by students in online learning during the Covid-19 pandemic. The instrument used was a questionnaire on the feasibility of learning media, the suitability of the material, and the Lithium application. The results of the evaluation of the media expert validator and the material expert respectively obtained the value of relevance and consistency of 3.15 (valid); 3.00 (valid); and 3.65 (very valid). This means that the Lithium application can be used as an online learning medium by utilizing Android as a solution to reduce high school students' misconceptions of chemical equilibrium material
Application of Cooperative Learning Jigsaw Model to Improve Student's Learning Achievement in Chemistry Learning
Get PDFThis study aims to improve student achievement in learning chemistry in class X MIA4 at SMA Negeri 1 Palu by applying the Jigsaw Cooperative Learning Model. The Classroom Action Research (CAR) problem can be formulated as follows: Is the Jigsaw Cooperative Learning Model application able to improve student achievement in learning chemistry in class X MIA4 SMAN 1 Palu? CAR is carried out with the following stages to answer the problem: 1. Planning, 2. Implementation. 3. Observation, and 4. Evaluation and Reflection. The study results can be explained as follows several fundamental aspects of learning were successfully improved by applying the Jigsaw Cooperative Learning Model. Such as student activity in collaboration and in completing worksheets independently, actively asking and answering questions, and making students feel happy and enthusiastic. Likewise, the average evaluation of each cycle showed that the % completeness increased. In cycle one, action one was 73.8%, action two 85.5%, and activity three 92.9% increased in cycle two, the average from three actions to 98.0%. It can be concluded that the application of the Jigsaw Cooperative Learning Model can improve student achievement in class X MIA4 SMA Negeri 1
Manufacture Indicator Paper for BSL or Small Bungur Extract (Lagerstroemia Indica L) as an Indicators Alternative of Acid-Base
Get PDFThis study aims to utilize extracts of local cherry blossoms or small bungur (Lagerstroemia Indica L) in the manufacture of indicator paper as an alternative acid-base indicator. Local Cherry Blossoms were macerated with methanol for ± 2 hours. Extracts and indicator paper of local cherry blossoms were tested as indicators in an acid-base solution, the buffer was then compared with phenolphthalein and methyl orange indicators for acid-base titration, namely strong acid and strong base, weak acid and strong base and weak base and strong acid. The results obtained in this study are: local cherry blossom extract is brownish yellow, in a strong acid it is pink, in a strong base it is dark green, in a weak acid it is pale pink and in a weak base it is light green. The indicator paper of local cherry blossom extract in strong acid is light pink, a strong base is yellow, a weak acid is pale pink, and a weak base is light green. In the buffer, the indicator paper of local cherry blossom extract has a pH range of 4-5 colors (pink-green), and 7-11 colors (yellow-green), the stability of the indicator paper from filter paper can maintain its color for 25 days. The type of acid-base titration that is suitable for the use of local cherry blossom extract indicators, precisely in the titration of strong acid-strong base and the weak acid-strong base is good to use as a substitute for phenolphthalein indicator, while in weak base-strong acid titration it is better to use as a substitute for methyl orange
Plant-mediated Green Synthesis of Nanoparticles NiCoFe2O4 Photocatalyst Using Africa Leaves Infusion
Get PDFNanoparticles (NPs) can be synthesized using a simple and environmentally friendly method by utilizing infuse of the plant. The secondary metabolites contained in infused Africa leaves were used as reducing and stabilizing agents in the synthesis of NiCoFe2O4 NPs. The characteristics and photocatalytic activity of NiCoFe2O4 against the photodegradation of diazinon have been investigated using UV-Vis, FTIR, XRD, and SEM. The UV-Vis spectra showed that NiCoFe2O4 had been formed, as established with a maximum absorbance peak at 277 nm. The FTIR results also confirmed the presence of a ferrite spinel group at a wave number of 565cm-1. The XRD diffractogram showed a cubic crystal of NiCoFe2O4 with a size of 8.79 nm, which was also confirmed from the SEM images that the NPs were slightly agglomerated with an average size of 94.37 nm. The photocatalytic performance of NiCoFe2O4 against diazinon which was carried out for 300 minutes under UV light obtained a degradation percentage of 72.40% producing diazoxide, 2-isopropyl-6-methyl-4-pyramidal (IMP) and diethyl phosphonate. It was concluded that infused African leaves had an active role in the synthesis of NiCoFe2O4
Utilization of Hyperdocs in Online Learning Models on Student Learning Outcomes
Get PDFThis 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
Application of CORE Learning Model with Molymod-Assisted on Hydrocarbon Material to Improve the Students’ Learning Outcomes
Get PDFThis study aimed to describe the improvement of learning outcomes by applying the learning model of Connecting, Organizing, Reflecting, Extending (CORE) with molymod-assisted hydrocarbon material of class X students of SMA Labschool UNTAD Palu. This type of research was experimental designs with one group pretest-posttest design. This study used 2 classes, namely class XA as replication class 1 (n = 26) and class XB as replication class 2 (n = 27). The students' learning outcomes were affective, psychomotor, and cognitive aspects. In replication class 1, the value of student learning outcomes was 71.37, while in replication class 2 was 66.00. The data analysis results showed increased student learning outcomes after using the Molymod-assisted CORE learning model in both classes. So it can be concluded that applying the Molymod-assisted CORE learning model on hydrocarbon materials can improve student learning outcomes for class X SMA LABSCHOOL UNTAD Palu
Identification of Student Misconception using a Three-tier Diagnostic Test on Colloid
Get PDFThis study aims to identify the percentage of misconceptions that occur in students on colloid material in class XI MIPA 2 SMA Negeri 1 Dampal Selatan Kabupaten Tolitoli is based on the results of a three-level diagnostic test and shows which subconcepts have the highest and lowest conceptions. The instrument used in this study was a three-level multiple choice diagnostic test. The results showed students' misconceptions about colloid material in class XI MIPA 2, which was 65.51%. The results of this study indicate that the level of students' misconceptions about colloidal material is a high category
Phospate Release Study on Silica Gel and Amino Silica Hybrid Sorbent from Lapindo Mud
Get PDFThis 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
Calcium Extract Characterization from Rajungan Crab Shell (Portunus pelagicus) and Bakau Crab Shell (Scylla serrata) using Calcination as Effervescent
Get PDFOne 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 Potential of Crude Extract Bromelain Enzyme on Production of Virgin Candlenut Oil (VCdO)
Get PDFVirgin 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