Jurnal Akademika Kimia

Application of Snowball Throwing Model in Science Subjects on Student Learning Outcomes at Junior High School

Hayyatun Mawaddah , Lestari M.P Alibasyah — Tue, 25 Feb 2025 00:00:00 +0000

This 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.

Determination of Citric Acid Level in Starfruit (Averrhoa bilimbi L.) and Starfruit Raisins

Sri Rahayu, Siti Nuryanti — Tue, 25 Feb 2025 00:00:00 +0000

Citric acid is one of the plants in Indonesia that has many benefits in various fields, especially in the industry. This study aims to determine the levels of citric acid in starfruit (Averrhoa Bilimbi L.) and starfruit raisins in Oti Village, Sindue Tobata District, Donggala Regency. The analytical method used to determine the levels of citric acid is alkalimetric titration. The sample used in this study came from Oti Village, Sindue Tobata District, Donggala Regency. The percentage results showed that the levels of starfruit citric acid were 6.363 %, and the starfruit raisins were 4.703 %.

Determination of the Content of Nitrogen (N), Phosphorus (P), and Potassium (K) in Pellets from Cakalang fish (Katsuwonus pelamis) Waste Fermented Using Adhesives From Broiler Chicken Feces

Iin Safitri, Paulus H. Abram — Tue, 25 Feb 2025 00:00:00 +0000

Fish offal and broiler faeces are underutilised organic waste; the purpose of this study was to determine the levels of nitrogen (N), phosphorus (P) and potassium (K) contained in the pellets from cakalang fish (Katsuwonus pelamis) waste fermented using adhesive from broiler chicken faeces. Nitrogen levels were determined using a colourimeter, phosphorus levels were determined using a UV-Vis spectrophotometer, and potassium levels were determined using a flame photometer. The results showed that the analysis of nitrogen, phosphorus, and potassium in the pellets from the fermentation of cakalang fish waste obtained an average of 4.2 %, 2.21 %, and 3.85 %, respectively.

Antioxidant Activity Test of (Acalypha indica L) Extract

Nursafitri Nursafitri, Tri Santoso — Tue, 25 Feb 2025 00:00:00 +0000

The antioxidant activity test of Acalypha indica L has been carried out. This study aimed to determine the IC₅₀ value of the Acalypha indica L extract. The radical concentration of 2,2-diphenyl-1-picrylhydrazyl (DPPH) after adding Acalypha indica L extract was determined using a UV-Vis spectrophotometer. The concentration variations used in Acalypha indica L extract were 15.48 ppm, 30.96 ppm, 46.44 ppm, and 61.92 ppm. The results showed that the IC₅₀ value of Acalypha indica L extract was 41,259 ppm, while the IC₅₀ value of vitamin C as a comparison was 50.626 ppm. Based on the IC₅₀ value data above, it can be seen that the antioxidant of Acalypha indica L extract is robust compared to vitamin C.

Application of Discovery Learning Model to Improve Student Science Process Skills in Colloid Material on Senior High School

Mahdayanti Lationo, Kasmudin Mustapa — Tue, 25 Feb 2025 00:00:00 +0000

This study aimed to describe the improvement of students' science skills by applying the discovery learning model to the colloid material of class XI IPA SMA Negeri 1 Ampibabo. The research method used was pre-experiment with one group pretest-posttest. The sample in this study consisted of students from class XI IPA as experimental class 1, which was planned for 30 students, and class XI IPA B as class experiment 2, which meant 30 students. The instrument used was a science skills test, student activity observation sheets measured using six aspects, namely, observation, asking questions, hypothesizing, classification, interpreting data, and communicating) and student response questionnaires. The results of the study were obtained from the science skills test scores, the pretest, and the hottest of the two classes; namely, the average pretest score for class XI IPA A was 11.66 % and class XI IPA B was 13.3 %, while the average posttest score was 11.66 %. Obtained from class XI IPA B of 75.48% and class XI IPA B of 75.97 % The results of the analysis of the six aspects of science process skills of students in class XI IPA A obtained an average of 75.52 % and class XI IPA B was obtained an average of 78.64 %. Based on the study results, it can be ignored that the application of discovery learning models can improve students' skills in colloid material in class XI IPA SMA Negeri 1 Ampibabo. This can be seen from the proportion of the average student response, which is 90.61 % strongly agree with the discovery learning model.

Examining Student Conception of Reaction Rate Through Three-Tier Multi-Representation Assessments

Tue, 25 Feb 2025 00:00:00 +0000

This study aims to analyze students' conceptions of reaction rate topics using the three-tier multi-representation test. Based on the characteristics of reaction rates concepts that involve the understanding of multiple representations, it is essential to analyze student conceptions that include multiple representations, namely macroscopic, microscopic, and symbolic. A three-tier diagnostic test can be done to assess students' conceptions, with the questions given in the first tier presented with macroscopic, microscopic, or symbolic representations according to the characteristics of the concept in question. This research uses a descriptive quantitative method conducted at Madrasah Aliyah Negeri 2 in Palu City, Central Sulawesi. The subjects of this study were 50 students consisting of 28 female students and 22 male students. It was determined by random sampling technique. Instrumentation used a three-tier representation test with 15 multiple-choice questions. Validation of instruments showed that the questions were feasible and fell into the high category. The findings reveal that only 29 % of students know the concept, categorized as low. Additionally, 40 % of students were identified as having misconceptions, placing them within the medium category, while 31 % of students exhibited not knowing the concept, also classified in the medium category. Symbolic representation emerged as the most challenging representation for students, with 35 % failing to comprehend it, categorized as medium. Furthermore, among students with misconceptions, symbolic and macroscopic representations were the most problematic, collectively accounting for 34 %, also classified as medium. These results underscore the need for targeted instructional strategies to address specific areas of difficulty and improve overall conceptual understanding.

Analysis of Potassium (K) and Calcium (Ca) in Durian Seeds (Durio Zibethinus Murr)

Gita Fahira, Irwan Said — Tue, 25 Feb 2025 00:00:00 +0000

Durian seeds are one of the wastes from durian fruit that has not been optimally utilized due to the community's lack of knowledge and creativity regarding the processing of waste into food that has economic value. This reduces the accumulation of durian seed waste that can pollute the surrounding environment. Durian seeds benefit from being used as food because they are rich in minerals, especially potassium and calcium. This study aims to determine the levels of potassium and calcium contained in durian seeds. Determination of potassium and calcium levels using atomic absorption spectrophotometer (SSA). Potassium levels were analyzed at a wavelength of 766.8 nm, and calcium was investigated at 423 nm. Before the potassium and calcium levels were determined, the moisture content and ash content were first defined in the sample. The results of the analysis of moisture in the sample obtained 2.182 % and ash content of 12.633 %. Further analysis of potassium obtained average results for potassium of 612.605 mg / 100 g and an average for calcium of 15.555 mg / 100 g. The results of this study are expected to be a source of information about potassium and calcium levels in durian seeds. They can be further utilised as an alternative food based on durian seeds, especially in the Parigi Moutong area, Central Sulawesi.

Characteristics of Critical Thinking Skills of Class XI Senior High School on Stoichiometry Material

Sinta Devi, Afadil Afadil — Tue, 25 Feb 2025 00:00:00 +0000

This study aims to describe the characteristics of students’ critical thinking skills in the Stoichiometry material of class XI SMA Negeri 1 single. This type of research is descriptive quantitative. The sample of this research was all students of class XI SMA Negeri 1 Sindue, which consisted of 3 classes, namely class XI MIA 1, XI MIA 2, and XI MIA 3. The data in this study were obtained through a test of students' critical thinking skills in the form of essays with as many as five items. Three essential thinking indicator items are interpretation, analysis, and inference. The results of data analysis for students' critical thinking skills for indicators of interpretation, analysis, and inference showed that class XI MIA 1 obtained the percentage results for the interpretation indicator 40,5 % in the low category, the analysis indicator obtained by the percentage of 35 % was included in the low category, and indicator inference obtained a percentage of 17 % who are in the very low category. Class XI MIA 2 obtained the percentage result on the interpretation indicator 46 %, which is in the low category. In comparison, the analysis indicator obtained a percentage of 59.5 % who are in the low category, and indicators inference obtained a percentage of 25,5 % who are in the low category. Whereas in class XI MIA 3, the percentage of interpretation indicators was 44 % in the low category, the analysis indicators obtained a percentage of 57,5 % who were in the low category. The inference indicator obtained 23,5 % who were in the very low category. Based on the research results at these schools, it can be seen that the critical thinking skills of class XI students of SMA Negeri 1 Sindue are still very low.

Analysis of Carotene in Biscuits made from Yellow Pumpkin Flour (Cucurbita moschata Durch) at Various Heating Temperatures

Yuldayani, Supriadi — Tue, 25 Feb 2025 00:00:00 +0000

Yellow 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.

Study of Ethanol Extract of Karamunting (Rhodomyrtus tomentosa (Aiton) Hassk) as Acid-Base Bioindicator

Wiwit wiwit, Anang W. M Diah — Tue, 25 Feb 2025 00:00:00 +0000

Karamunting or Rhodomyrtus tomentosa (Aiton) Hassk is a fruit that contains anthocyanins. This study aimed to determine the potential of the ethanol extract of this fruit as an acid-base bioindicator. Karamuting fruit was macerated using three solvents (n-hexane, ethyl acetate, and ethanol) for 24 hours. The extract of the karamunting fruit was tested as indicators in acid-base solutions and buffer solutions and compared with phenolphthalein and methyl orange for acid-base titrations, namely: Strong acids with strong bases, weak acids with strong bases and weak bases with strong acids. The results showed that the ethanol extract of karamunting fruit was brown, in strong acids was red, in strong bases was dark green, in weak acids was pink, and in weak bases was light green. Furthermore, the kara munting fruit indicator extract buffer solution gave four groups of colour changes, namely, at pH 1, it was red; at pH 2 to 6, it was pink; at pH 7 to pH 10, it was light green; and at pH 11 to 12, it was dark green. The ethanol extract of karamunting fruit can be used as an acid-base indicator because it gives equivalent results to comparative indicators, namely phenolphthalein and methyl orange.