Jurnal Akademika Kimia
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Development of an E-Handout Based on Discovery Learning on The Reaction Rate for Class XI Students
Get PDFThis study aims to determine the level of feasibility, practicality, and the students' readability response to e-handout-based discovery learning. This development research uses 4-D development models developed by S. Thiagarajan, Dorothy S. Semmel, and Melvin 1 Semmel. The 4-D development model has four stages: the Define stage, the Design stage, the Development stage, and the Disseminate stage, but this study is limited to 3-D: the Define stage, the Design stage, and the Development stage. The subjects in this study were 3 material experts and media experts, five chemistry subject teachers, and the readability response of MIPA 1 class XI students, with 33 people. Data collection instruments include an interview sheet, an e-handout assessment sheet by a material expert validator and a media expert, a practicality sheet by a teacher, and a student reading response sheet. Data analysis techniques use qualitative and quantitative data. Based on the results of the study, an analysis of the needs of students showed that students agreed that it was necessary to develop an e-handout based on discovery learning on the reaction rate material. Then, assessment by material expert validators of an 85% well-deserved e-handout, assessment by media expert validators of an 86% well-deserved e-handout, teacher practicability of an 88% well-deserved or very practical e-handout, and 87% of students' readability response to e-handouts is said to be very decent or very high
Determination of Tanin Extract of Belimbing Wuluh Leaves (Averrhoa Bilimbi L.) by Uv-Vis Spectroscopy Methods
Get PDFWuluh star fruit plant (Averrhoa bilimbi L.) was a traditional medicinal plant that was rarely utilized as a natural medicine and contained many secondary metabolite compounds, one of which was tannin. This study aimed to determine the type of tannin and the amount of tannin content in belimbing wuluh leaves. Wuluh star fruit leaf powder was extracted by the maceration method using 96 % ethanol solvent, and then the filtrate was concentrated by rotary evaporator. Identification of tannin types in the extract was performed using CH3COOH 10 %, (Pb(CH3COO)2) 10 %, HCl, FeCl3, and KBr. For analysis of tannin content, Folin-Ciocalteau reagent and 15 % Na2CO3 solution were added, and then analyzed using UV-Vis spectrophotometry at a wavelength of 765 nm. The results of the identification of tannin types showed that belimbing wuluh leaves included condensed tannins, and the results of the analysis showed that the tannin content was 7.282 mg/g extract
The The Relationship Between Body Image Satisfaction and Nutritional Status in Female Students of High School
No full textIn the adolescent phase, there is physical, social, and psychological development and growth. These changes will affect the way adolescents view and behave towards their body, known as body image. Appearance is important for adolescent girls, so most adolescent girls try to meet society's beauty standards by fasting, dieting, exercising, taking laxatives, and diet pills. The behavior of restricting diet and living an unhealthy lifestyle can affect adolescent nutrition, such as anemia, malnutrition, and obesity. This study aims to determine the relationship between body image satisfaction and nutritional status in SMA Negeri 5 Palu students. This study uses an observational analysis method with a cross-sectional design. The sample in this study amounted to 92 respondents. The sampling technique used was proportionate stratified random sampling. The bivariate analysis test used the Spearman test. The results of the Spearman test showed a p-value = 0.097 (p>0.05), which means that there is no relationship between body image satisfaction and nutritional status in SMA Negeri 5 Palu students. There is no relationship between body image satisfaction and nutritional status in female students of SMA Negeri 5 Palu
The Effect of the PBL Model on Literacy and Numeracy Skills in Acid-Base Material
Get PDFProblem-Based Learning is a learning model that focuses primarily on problems in the learning process. It encourages students to collaborate in groups to solve problems through various activities. The purpose of this study was to determine the effect of the Problem-Based Learning (PBL) model on students' numeracy literacy skills in acid-base material. This study used a quantitative, true-experimental design. The research population consisted of 47 students. The research sample was obtained using purposive sampling, divided into an experimental class of 15 students from class XI MIA 2 and a control class of 16 students from class XI MIA 1. The research instruments included a literacy test comprising 20 multiple-choice questions and a numeracy test comprising five essay questions. Experts validated all instruments provided. Data analysis used the Mann-Whitney test. The results of the data analysis showed that the Mann-Whitney test p-value (0.000) was lower than the predetermined significance level of 0.05. Therefore, it can be concluded that the PBL learning model affects students' numeracy literacy skills
Analysis of Carotene in Biscuits made from Yellow Pumpkin Flour (Cucurbita moschata Durch) at Various Heating Temperatures
Get PDFYellow pumpkin (Cucurbita moschata Durch) is one of the food ingredients rich in dietary fibers, especially pectin, bioactive compounds, beta carotene, vitamin A, tocopherol, other vitamins including B6, K, C, thiamine, and riboflavin, as well as several types of minerals (K, P, Mg, Fe, and Se). This study aimed to determine the carotene retention of biscuits made from pumpkin flour (Cucurbita moschata Durch) at various heating temperatures. This study's stages included preparing pumpkin flour and biscuits, carotene content, and carotene retention analysis from various heating temperatures. Determination of carotene retention using a UV - Vis spectrophotometer. The results showed that the roasting temperature influenced carotene retention in the preparation of biscuits. Biscuits with retention of 86 % were found at a temperature of 190 oC. The lowest carotene retention of 79 % was found at a roasting temperature of 210 oC
Application of Snowball Throwing Model in Science Subjects on Student Learning Outcomes at Junior High School
Get PDFThis study aimed to describe the effectiveness of the snowball-throwing learning model in improving student learning outcomes in science subjects in junior high school. This quantitative descriptive research uses an experiment method and pretest-posttest one-group design. The research population was all VIII class students of Junior high school, 19 Palu in the 2022 / 2023 school year, totalling 107 people, with a research sample of VIII A class totalling 31 people. The sample was determined using a non-probability sampling technique, a simple random sampling method. The research instrument consisted of an evaluation test and a teaching observation sheet. Data analysis was carried out using non-parametric statistics and the Wilcoxon signed rank test to test the hypothesis of pretest and posttest data. At the same time, the data from the student activeness observation sheet was carried out descriptively per cent. As for determining the effectiveness of the learning carried out, using the N - Gain test. The pretest and posttest data analysis results obtained a significant probability value < α (0.05). Thus, it can be stated that the proposed research hypothesis is accepted, and it can be noted that the snowball-throwing learning model is efficacious in improving student learning outcomes. Gain test results show that the efficacy of snowball throwing learning is high with an N - -gain value of 0.8, with an N score of 80 % in the practical category. This achievement is supported by the observations of student activeness, with a percentage of 81.8 % in the outstanding category. It can be concluded that the snowball-throwing learning model effectively improves student learning outcomes in science subjects at Junior high school 19 Palu
Analysis Levels of Calcium Oxide (CaO) in Limestone from Leok Village, Biau Sub-district, Buol District
Get PDFLimestone is one of the rocks that is very abundant in Indonesia and has many benefits, especially in the field of industry. This study aims to determine the levels of calcium oxide (CaO) in limestone at Desa Leok, Kecamatan Biau, Kabupaten Buol. XRF (X-ray fluorescence) was the analytical technique utilized to ascertain the amount of calcium oxide (CaO) present in the limestone. Both the coast area and the hill area provided samples. The measurement results indicate that the level of CaO is 92.41 % in the coast area and 93.74 % in the hill area
Proximate Composition Study of Biscuits from Durian (Durio Zibethinus Murr.) Seed Flour as Food Innovation
Get PDFBiscuits are one of the most popular snacks for the public, with the primary raw material being wheat flour. However, the high dependence on wheat flour encourages the need to find alternative ingredients that are more diverse and have high nutritional value. This study aims to analyze the proximate content (carbohydrate, protein, and fat) of biscuits made from durian seed flour (TBD), which is compared with cornstarch (TM) and wheat flour (TT). Proximate analysis methods included UV-Vis spectrophotometry for carbohydrate analysis, the Kjeldahl protein method, and Soxhlet fat extraction. The formulations used consisted of: F1 (100% TBD), F2 (100% TM), F3 (50% TBD:50% TM), and F4 (50% TT:50% TM). The results showed that the highest carbohydrate content was found in F1 at 70.07%, while the highest protein content in F4 at 13.65%. The highest fat content was found in F2 at 21.69%. The best formulation was obtained in F3 (50% TBD:50% TM) because it has a balanced nutritional composition and potential as a functional food product, especially for people with diabetes. In addition, this biscuit product has the potential as a contextual learning medium in food science and nutrition, especially in introducing proximate concepts and utilizing tropical fruit seed waste
Utilization of Black Tea Dregs as an Adsorbent of Metal Fe in Water using UV-Vis Spectrophotometry
Get PDFTea dregs are household organic waste materials that can be utilized as low-cost adsorbents for heavy metal removal. Previous studies mainly employed green tea dregs and focused on Cu(II) adsorption, while studies on Fe(III) adsorption using black tea dregs and their direct application to Fe-contaminated water remain limited. This study evaluates the adsorption performance of black tea dregs toward Fe(III) ions and their application in water samples. Batch adsorption experiments were conducted using FeCl₃ solutions at pH 4.8 to determine the optimum contact time (15–90 minutes) and initial concentration (100–300 ppm). Fe(III) concentrations were analyzed using UV–Vis spectrophotometry. The results demonstrated an optimal contact time of 60 min and an optimal concentration, achieving 99.26% adsorption efficiency. Adsorption followed the Langmuir isotherm model with a maximum capacity of 37.04 mg/g (R² = 0.998). Application to well water samples resulted in 83.74% Fe removal, confirming the potential of black tea dregs as adsorbents
Analysis of Sodium Content and Estimated Daily Intake from Shellfish Consumption: Case Study in Banda Aceh
Get PDFThis study aims to analyze sodium (Na) levels and estimate the daily intake (EDI) from the consumption of three shellfish species: blood mussels (Anadara granosa), kepah (Polymesoda erosa), and nipah (Geloina coaxans) obtained from Al Mahira Market and the Alue Naga area in Banda Aceh. Sodium concentrations were determined using Atomic Absorption Spectrophotometry (AAS). The results showed that sodium levels ranged from 1186 to 4656 mg/kg (wet weight). The highest EDI was found in blood mussels from Al Mahira Market at 0.997 mg/kg body weight/day (3.489% of the recommended daily sodium intake). In comparison, the lowest was observed in nipah clams from the exact location at 0.247 mg/kg body weight/day (0.866%). Overall, sodium intake from shellfish in both locations contributed less than 5% of the daily sodium limit. These findings indicate that shellfish consumption poses a low sodium-related health risk, although frequent or high intake may still contribute to long-term hypertension risk