Jurnal Pendidikan Kimia
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Developing Small Scale Chemistry Practicum Module to Identify Students’ Ability in Predict-Observe- Explain (POE) Implementation
Get PDFChemistry practicum does not have to be complicated and requires expensive apparatus and chemicals, and is considered not environmentally friendly. The concept of small scale chemistry practicum is one of appropriate technology that is packaged elegantly to introduce and embed the principles of green chemistry in every chemistry experiments, and also to enhance the concepts of chemistry through verification and scientific discovery. This study aims to create the newest product, the small scale chemistry practicum module to identify the ability of the students of chemistry education study program, Sanata Dharma University, Yogyakarta in formulating predictions on phenomenon based on the insights they have, making direct observations through small scale chemistry practicum, and explaining the results of observations and emphasis on concepts in detail and depth. This research is the development research with the model of Analysis, Design, Develop, Implement, and Evaluate (ADDIE). Data were analyzed by descriptive analysis and Rasch Model. The results of the study show that the product developed has a perfect and feasible level of readability to be tested. From the content aspect, it presented in perfect criteria, as well as the construction aspect and aspect of language, also shows good value. The students already have quite an excellent ability to predict (average score= 76), observe (average score= 88.5), and explain (average score 87.5). Also, it was noted that students enthusiastically applied POE, and the results of POE students show good person reliability value (0.88) in small scale chemistry experiments. The product developed has been valid, effective, and practical for use in experiments according to experts and teachers, and good student responses (Cronbach's alpha value= 0.92) to the product
Using Think-Pair-Share to Develop Students' Social and Emotional Competencies in Chemistry Learning
Get PDFThe aim of this study was to analyze students' social and emotional competencies through the integration of Think Pair Share (TPS) and a Social and Emotional Learning (SEL) approach to topics related to Acids and Bases. Social and emotional learning (SEL) is the process through which children and adults understand and manage emotions, set and achieve positive goals, feel and show empathy for others, establish and maintain positive relationships, and make responsible decisions.. The study involved thirty-five 11th grade students in one of private school in Jakarta and was conducted between January and April, 2017. A qualitative methodology was employed to analyze students’ social and emotional competencies using interviews, classroom observations, reflective journals, and student worksheets. The application of a SEL approach was carried out by integrating it with a TPS strategy. In the Think stage students were given the opportunity to explore their understanding of acids and bases and to solve problems individually. In the Pair stage they could communicate their insights to the group, and in the Share stage they had occasion to present their group perspectives and respond to others. The five social and emotional competences found in this study were; self awareness, self management, social awareness, relationship management, and responsible decision making. Self awareness was demonstrated by understanding a student’s abilities, their needs, and their self- confidence. Self management was indicated by a student’s ability to manage pressure, plan strategies, and seek help. Social awareness competencies were analyzed through the development of students' attitudes to diversity and how they demonstrated care for friends. Relationship management competencies were identified by observing a student’s ability to manage friendships, how they overcame differences, and whether they provided assistance to each other. The responsible decision making competency was determined by observing how students made decisions when trying to solve a problem and whether they were able to plan a strategy when facing pressure. Whilst integrating SEL the researchers were challenged by the need to empower students, encourage teachers to stimulate students’ social and emotional competencies, and to manage time constraints. Integrating SEL into chemistry learning provided opportunities for students to develop their social and emotional competencies through independent thinking activities, group discussions, and presentations to their peers
Reconstruction of Practice Module on the Adsorbent Topic Contained the Nature of Science (NOS)
Get PDFThe training module is a learning material with interesting illustrations, communicative language, and can be adapted to students' knowledge. Through this module, students can apply their knowledge to life. This study aims to reconstruct the practice module on the topic of adsorbents contained in NOS. The research design of the Educational Reconstruction Model (MER) as the primary reference in making the adsorbent practice module. The participant used was one of the secondary schools in the city of South Tangerang. The results of the calculation of the Content Validity Ratio (CVR) and Content Validity Index (CVI) show that the chemical concepts presented are valid and do not need to be improved. Test results show that from 30 student respondents, the overall percentage data was 89.8%, which means that this module is excellent and suitable as a source of learning in schools. The results of this study can be used as an example of innovating teaching materials.
Cytotoxic Activity Against L1210 Leukemia Cells from the Ethyl Acetate Fraction of Kenikir Leaves (Cosmos. Caudatus) Preserved by Gamma Irradiation
Get PDFKenikir leaves (Cosmos caudatus) Has been used as traditional medicine, especially as an anti-cancer, this plant has been in Indonesia both in herbs and capsules. Microbial contamination of herbal medicinal raw materials occurs when the storage process is done. One of the preservation techniques used in the industry is using gamma irradiation techniques to reduce microbial and fungal contamination. The purpose of this research was to study the effect of gamma irradiation for the preservation of kenikir leaves (C. caudatus) as an anti-cancer based on cytotoxic activity using L1210 leukaemia cells. The simplicia was gamma-irradiated by Co-60 source with variation doses of 0 (control); 5; 7.5; 10; and 15 kGy. Then the irradiated and control samples were macerated successively using n-hexane, ethyl acetate, and ethanol. The active extract (ethyl acetate) was further fractionated using column chromatography, obtained seven fractions (F1 - F7). The seven fractions' cytotoxic activity against L1210 leukaemia cells showed that fraction 3 (F3) was the most active fraction with an IC50 of 1.26 µg/mL. Each dose's F3 cytotoxic activity showed that the IC50 7.5 kGy irradiation sample did not change significantly with control (0 kGy) based on ANOVA analysis using SPSS 24 with a 95% confidence level. In comparison, irradiation samples of 10 and 15 kGy showed a change in the IC50 value is significant with the control (0 kGy). These results indicate that gamma irradiation can be used as an alternative for preserving C. caudatus with a maximum dose of 7.5 kGy, so that its anti-cancer properties do not change with those without irradiation
Digital Literacy Analysis of Chemistry Education Students in Using the ChemDraw Application
Get PDFStudents digital competence abilities can be measured using the individual competence framework. There are five indicators used: information, communication, content creation, safety, and problem-solving. This study analyses students digital literacy profile with high, medium, and low ChemDraw skills. This research is a qualitative descriptive study. The trial was conducted on 25 Chemistry Education Students at UIN Walisongo Semarang with high, medium and low ChemDraw skills. Data were obtained using ChemDraw test instruments, observation and questionnaires. The data obtained were analysed based on digital literacy indicators to obtain student digital literacy profiles. The results showed that the digital literacy level of students with high ChemDraw skills had a moderate level of digital competence. Students with medium ChemDraw skills have a moderate level of digital competence. Meanwhile, students with low ChemDraw skills have a low level of digital competenc
The Comparison of Spectrophotometric and TLC-Densitometric for DPPH Radical Scavenging Activity Analysis of Three Medicinal Plant Extracts
Get PDFIn this research, Thin Layer Chromatography-Densitometry has proven to be a good method for analyzing 1, 1 diphenyl 2-picrylhydrazyl (DPPH) radical scavenging activity, since this approach displayed the similar trends with UV-Vis spectrophotometric method. Three medicinal plants collected from Semarang used to evaluate both methods. The IC50 value ranged from 25.26 - 4913.74 ppm shown by UV-Vis spectrophotometric and 24.74 – 4674.61 ppm using TLC-Densitometric. Meniran Dechlorophyllated (Phyllanthus niruri) provides the strongest antioxidant activity and the weakest de-chlorophylated parsley (Petroselinum crispum). The paired sample t-test points from a non-dechlorophylation extract using the TLC densitometry test significantly gives a lower IC50 value than the UV spectrophotometry method-has. The maximum increase of peak area under the UV light 365 nm up to 56.08 %. This evidence supports the presumption that the scavenging radical DPPH caused not only decreasing the maximum absorbance under UV light 516 nm but also increasing the absorbance under UV light ± 365 nm
The Development of Scaffolding in Inquiry-Based Learning to Improve Students' Science Process Skills in The Concept of Acid and Base Solution
Get PDFThe technique of providing learning support in a structured manner to encourage students to learn independently is called scaffolding. This consists of four types questioning, prompting, cueing, and explaining. This study aims to describe the procedure for developing scaffolding in inquiry-based learning that is beneficial to improve students' science process skills in the concept of acid and base solution. The heuristic method in the type of F2-O3-S1+S5+S6-A3 was used in this study to develop the design of the scaffolding. The data were collected using an interview and analyzed using a Delphi technique. Based on the expert validation, it was seen that the scaffolding technique designed was suitable for use. The results of the student trial also showed that the scaffolding technique was effective to be used to improve students' science process skills. It can be concluded that the scaffolding technique on inquiry-based learning was able to improve students' science process skills in the concept of acid and base solution
QSAR Modeling of Compounds Derived from 1,2,3-Triazolopiperidine as DPP-4 Enzyme Inhibitors Using Semiempirical AM1
Get PDFThis study aims to model the derived compounds of 1,2,3-triazolopiperidine using semiempirical method AM1 and determine the further derivation with the better IC50 values against DPP-4 enzyme theoretically. This research employed ChemDraw Pro 12 software for for 2D structural drawing, Hyperchem 8.0 for 3D modelling, and MLR statistical analysis for modeling QSAR equations. The semiempirical method was likely to be the appropriate platform to apply because the correlation coefficient of H1 NMR chemical shift between theoretical and actual value is relatively close, 0.8891. The multilinear regression analysis produced 4 equation models where the best one is equation 4 as detailed below:” IC50 = 875,5116 + (-7400,27*qH35) + (-0,00133* Eat.is) + (-3230,72* qN23) + (3,30277* µ)” n = 25; r2 = 0,594; Adjusted r2= 0,486; PRESS = 1,2× 104. Finally, the theoretically promising substituent was -CN possessing IC50 value = 1.61 nM.