Antioxidant compounds is one of compounds are needed by the body to reduce free radicals. The ability of antioxidants to reduce free radicals is called antioxidant capacity. The purpose of this study was to provide information on the total antioxidant capacity of the methanol extract of cocoa beans with the DPPH (2,2-Diphenyl-1-Picrylhydrazyl) method using spectrophotometer uv-vis. The crude extract obtained was extracted using methanol solvent by maceration method. The results of the phytochemical screening test on the methanol extract of cocoa beans showed the presence of flavonoids and tannins. The total antioxidant capacity test of cocoa bean extract used the standard equivalent value of gallic acid which has been shown to have a strong antioxidant ability to reduce DPPH free radicals at a wavelength of 517 nm. The results of the measurement of total antioxidant capacity in the variation of treatment, namely sun-dried cocoa beans and oven cocoa beans were 27.730 and 42.454 mg/mL GAEAC. Based on the results of this study, it was found that the ethanol extract of oven cocoa beans had the greatest total antioxidant capacity, namely 42.454 mg/mL GAEAC.
{"title":"Kapasitas Total Antioksidan Ekstrak Metanol Biji Kakao (Theobroma cacao. L) Dengan Metode Spektrofotometri Uv-Vis","authors":"Agung Ari Chandra Wibawa","doi":"10.33394/HJKK.V9I1.3794","DOIUrl":"https://doi.org/10.33394/HJKK.V9I1.3794","url":null,"abstract":"Antioxidant compounds is one of compounds are needed by the body to reduce free radicals. The ability of antioxidants to reduce free radicals is called antioxidant capacity. The purpose of this study was to provide information on the total antioxidant capacity of the methanol extract of cocoa beans with the DPPH (2,2-Diphenyl-1-Picrylhydrazyl) method using spectrophotometer uv-vis. The crude extract obtained was extracted using methanol solvent by maceration method. The results of the phytochemical screening test on the methanol extract of cocoa beans showed the presence of flavonoids and tannins. The total antioxidant capacity test of cocoa bean extract used the standard equivalent value of gallic acid which has been shown to have a strong antioxidant ability to reduce DPPH free radicals at a wavelength of 517 nm. The results of the measurement of total antioxidant capacity in the variation of treatment, namely sun-dried cocoa beans and oven cocoa beans were 27.730 and 42.454 mg/mL GAEAC. Based on the results of this study, it was found that the ethanol extract of oven cocoa beans had the greatest total antioxidant capacity, namely 42.454 mg/mL GAEAC.","PeriodicalId":346446,"journal":{"name":"Hydrogen: Jurnal Kependidikan Kimia","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134249714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This researchi is want to knowithe test quality of items in the mid semester for XII Grade of SMA Negeri 1 PematangsiantarIin academic yearI 2020/2021 basic on terms of reliability test, validity, difficulty index, descriminationi index and disctractor. The research have used thecollecting data’s method was documentation and to collect some of test item, student answer sheet, answer key and so do interview to chemistry teachers in this school. Research used subject in this school were grade XII Science 1,2,and 3 of the science students of SMA Negeri 1 Pematangsiantar with total of subject 108 students based on purposive sanpling that researcher which has been used. The research have used method ofIanalyzed was quantitative descriptiveIconducted and it has used softwere program based of SPSSIversion 25 and Anates version 4.0.9. The result of the research concluded that the quality of the test item has some of category such as showed 2 items (10%) had very good quality and 2 items (10%)too had poorIquality of test and extremely poor quality in same test and should be suggest to thrown awayand 8 items (40%) known that has good quality, 4 (20%) has moderately quality, 3 (15%) has poor quality of item test and conclude that the quality of item test had moderately good quality based on this research.
本研究以信度测试、效度测试、难易指数测试、鉴别指数测试和分项测试为基础，了解2020/2021学年SMA Negeri 1 - pematangsiata 12年级中期测试项目的测试质量。本研究采用了文献资料收集的方法，收集了部分试题、学生答题卡、答案等，对该校化学教师进行了访谈。本研究使用的研究对象为SMA Negeri 1 Pematangsiantar 12年级理科1、2、3年级理科学生，根据研究者使用的有目的抽样，共108名学生。本研究采用了定量描述分析的方法，采用了基于SPSSIversion 25和Anates version 4.0.9的软件程序。研究的结果得出结论,测验项目的质量有一些类别,如显示2项(10%)有很好的质量和2项(10%)也poorIquality测试和极度贫困的质量相同的测试,应该建议扔awayand 8项(40%)知道质量好,4例(20%)有中度质量,3例(15%)有质量差的产品测试,并得出结论,项目的质量测试基于这项研究有比较好的质量。
{"title":"Analisis Kualitas Butir Soal Buatan Guru Kimia Pada Tes Ujian Tengah Semester Ganjil Kelas XII MIPA","authors":"H. Simamora, H. Hartono, Effendi Effendi","doi":"10.33394/HJKK.V9I1.3701","DOIUrl":"https://doi.org/10.33394/HJKK.V9I1.3701","url":null,"abstract":"This researchi is want to knowithe test quality of items in the mid semester for XII Grade of SMA Negeri 1 PematangsiantarIin academic yearI 2020/2021 basic on terms of reliability test, validity, difficulty index, descriminationi index and disctractor. The research have used thecollecting data’s method was documentation and to collect some of test item, student answer sheet, answer key and so do interview to chemistry teachers in this school. Research used subject in this school were grade XII Science 1,2,and 3 of the science students of SMA Negeri 1 Pematangsiantar with total of subject 108 students based on purposive sanpling that researcher which has been used. The research have used method ofIanalyzed was quantitative descriptiveIconducted and it has used softwere program based of SPSSIversion 25 and Anates version 4.0.9. The result of the research concluded that the quality of the test item has some of category such as showed 2 items (10%) had very good quality and 2 items (10%)too had poorIquality of test and extremely poor quality in same test and should be suggest to thrown awayand 8 items (40%) known that has good quality, 4 (20%) has moderately quality, 3 (15%) has poor quality of item test and conclude that the quality of item test had moderately good quality based on this research.","PeriodicalId":346446,"journal":{"name":"Hydrogen: Jurnal Kependidikan Kimia","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130380603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ratna Sari Siti Aisyah, Solfarina Solfarina, Unita Yuliantika
High school students have difficulty in understanding “electrolyte and non-electrolyte” solution materials because they are mostly abstract. Students should study three aspects in electrolyte and non-electrolyte solutions including macroscopic, symbolic and submicroscopic. However, the fact that in school only accentuates macroscopic and symbolic levels. Then the learning resources cannot provide an explanation of the submicroscopic level and the learning model used does not make students active in accordance with the 2013 curriculum. This study aims to produce products in the form of problem solving-based Elnoel E-modules on electrolyte and non-electrolyte solution materials, as well as explaining the feasibility of E-elnoel module and student response to Elnoel E-module. This research is designed with ADDIE model with analyze, design, development, implementation and evaluation stages. This Elnoel e-module is validated by 7 experts (judment) that the results of material validation and media validation are declared valid with a value of 0.85 and 0.81. Then the Elnoel E-module was implemented to 9 students of grade XI science at Al-Qudwah Integrated High School to find out the student's response to the media developed by obtaining a percentage of 89% that belongs to the category very good.It can be seen that the development of media arranged based on problem solving can stimulate students’ thinking skills and get a positive response from students.
高中生在理解“电解质和非电解质”溶液材料方面存在困难，因为它们大多是抽象的。学生应该从宏观、符号和亚微观三个方面对电解质和非电解质溶液进行研究。然而，事实上，在学校只强调宏观和象征层面。那么学习资源就无法提供亚微观层面的解释，所使用的学习模式也没有按照2013年课程的要求让学生主动学习。本研究旨在生产基于电解质和非电解质溶液材料的基于问题解决的Elnoel e -模块产品，并解释E-elnoel模块的可行性和学生对Elnoel e -模块的反应。本研究采用ADDIE模型设计，分为分析、设计、开发、实施和评估四个阶段。该Elnoel e-module经7位专家(判断)验证，材料验证和介质验证的结果分别为0.85和0.81有效。然后在Al-Qudwah综合高中的9名11年级理科学生中实施Elnoel E-module，以了解学生对媒体开发的反应，获得89%的百分比，属于非常好的类别。由此可见，以问题解决为导向的媒介安排的发展，能够激发学生的思维能力，得到学生的积极响应。
{"title":"Pengembangan E-Modul Berbasis Pemecahan Masalah Pada Materi Larutan Elektrolit dan Non-Elektrolit (ELNOEL)","authors":"Ratna Sari Siti Aisyah, Solfarina Solfarina, Unita Yuliantika","doi":"10.33394/HJKK.V9I1.3715","DOIUrl":"https://doi.org/10.33394/HJKK.V9I1.3715","url":null,"abstract":"High school students have difficulty in understanding “electrolyte and non-electrolyte” solution materials because they are mostly abstract. Students should study three aspects in electrolyte and non-electrolyte solutions including macroscopic, symbolic and submicroscopic. However, the fact that in school only accentuates macroscopic and symbolic levels. Then the learning resources cannot provide an explanation of the submicroscopic level and the learning model used does not make students active in accordance with the 2013 curriculum. This study aims to produce products in the form of problem solving-based Elnoel E-modules on electrolyte and non-electrolyte solution materials, as well as explaining the feasibility of E-elnoel module and student response to Elnoel E-module. This research is designed with ADDIE model with analyze, design, development, implementation and evaluation stages. This Elnoel e-module is validated by 7 experts (judment) that the results of material validation and media validation are declared valid with a value of 0.85 and 0.81. Then the Elnoel E-module was implemented to 9 students of grade XI science at Al-Qudwah Integrated High School to find out the student's response to the media developed by obtaining a percentage of 89% that belongs to the category very good.It can be seen that the development of media arranged based on problem solving can stimulate students’ thinking skills and get a positive response from students.","PeriodicalId":346446,"journal":{"name":"Hydrogen: Jurnal Kependidikan Kimia","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129190641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Setiawan, Oktavia Sulistina, Habiddin Habiddin, Rucira Pavita
During the Covid-19 pandemic, learning is done online. Many students experience difficulties and decreased learning achievement while carrying out online learning. The reaction rate practicum learning media used at the high school level does not yet represent macroscopic, submicroscopic, and symbolic chemical concepts and has not been adapted to online learning. Multiple chemical representations can be applied using android-based learning media so that students are expected to understand the concepts in the reaction rate practicum. Android-based learning media is used to support the learning process. The purpose of developing android-based learning media on the reaction rate practicum concept is to produce android-based learning media and determine its feasibility. The development model used is the 4-D model by Thiagarajan, et al. The product developed in the form of an android-based reaction rate practicum learning media for students at senior high school. Based on the validation results indicate that the module is very feasible to use by meeting the percentage of 88.8%. The results of the readability test on the module obtained a percentage of 84.5%, so based on this assessment the module is very suitable for students to use as a learning resource and learning process in the classroom.
{"title":"Pengembangan Media Pembelajaran Berbasis Android Untuk Memfasilitasi Kebutuhan Pembelajaran Multiple Representation","authors":"N. Setiawan, Oktavia Sulistina, Habiddin Habiddin, Rucira Pavita","doi":"10.33394/HJKK.V9I1.3801","DOIUrl":"https://doi.org/10.33394/HJKK.V9I1.3801","url":null,"abstract":"During the Covid-19 pandemic, learning is done online. Many students experience difficulties and decreased learning achievement while carrying out online learning. The reaction rate practicum learning media used at the high school level does not yet represent macroscopic, submicroscopic, and symbolic chemical concepts and has not been adapted to online learning. Multiple chemical representations can be applied using android-based learning media so that students are expected to understand the concepts in the reaction rate practicum. Android-based learning media is used to support the learning process. The purpose of developing android-based learning media on the reaction rate practicum concept is to produce android-based learning media and determine its feasibility. The development model used is the 4-D model by Thiagarajan, et al. The product developed in the form of an android-based reaction rate practicum learning media for students at senior high school. Based on the validation results indicate that the module is very feasible to use by meeting the percentage of 88.8%. The results of the readability test on the module obtained a percentage of 84.5%, so based on this assessment the module is very suitable for students to use as a learning resource and learning process in the classroom.","PeriodicalId":346446,"journal":{"name":"Hydrogen: Jurnal Kependidikan Kimia","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126154812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Identification of Liquid Product Compounds from Natural Asphalt Pyrolysis from Lawele, Buton Regency has been carried out. This research is intended toidentify the content of the compounds contained in the liquid fraction from the pyrolysis of Lawele's natural asphalt. This is a research experimentwith natural asphalt material was simply pyrolyzed at a temperature of 350oC with a little vacuum. The resulting liquid products were analyzed using the GC-MS instrument and analysis showed that there were 24 compounds contained in the liquid fraction resulting from the pyrolysis of Lawele asphalt with 2 main components, namely Phenol (C6H6O) of 16.45% and acetic acid (C2H4O2) of 12.47%. Another important product is alkane derivatives, namely Undekane (C11H24) and cyclo-octene (C8H14) which can be used as fuel.
{"title":"Identifikasi Senyawa Penyusun Produk Cair Hasil Pirolisis Aspal Alam dari Lawele Kabupaten Buton","authors":"Rustam Musta, Muh. Siddik Ibrahim, Laily Nurliana","doi":"10.33394/HJKK.V9I1.3568","DOIUrl":"https://doi.org/10.33394/HJKK.V9I1.3568","url":null,"abstract":"Identification of Liquid Product Compounds from Natural Asphalt Pyrolysis from Lawele, Buton Regency has been carried out. This research is intended toidentify the content of the compounds contained in the liquid fraction from the pyrolysis of Lawele's natural asphalt. This is a research experimentwith natural asphalt material was simply pyrolyzed at a temperature of 350oC with a little vacuum. The resulting liquid products were analyzed using the GC-MS instrument and analysis showed that there were 24 compounds contained in the liquid fraction resulting from the pyrolysis of Lawele asphalt with 2 main components, namely Phenol (C6H6O) of 16.45% and acetic acid (C2H4O2) of 12.47%. Another important product is alkane derivatives, namely Undekane (C11H24) and cyclo-octene (C8H14) which can be used as fuel.","PeriodicalId":346446,"journal":{"name":"Hydrogen: Jurnal Kependidikan Kimia","volume":"26 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132644622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The aim of this study is to determine the misconceptions of Chemistry Mathematics course participants during online learning in Chemistry Education Study Program, University of Bengkulu in the 2020/2021 academic year. This research starts with an online learning process for 4 meeting using Zoom meeting application and Google Classroom using synchronous and asynchronous methods. The method used to detect misconceptions is to provide a Three tier multiple choice diagnostic test consisting of multiple choice question, clear reasons in the form of an essay, and the level of confidence in answering and giving reasons. The tool used in this research is attest tool in the form of a diagnostic test and non-test tool in the form of an interview. Data collection techniques were conducted through test sheets in the form of a Google Forms application and short interviews about diagnostic tests in the form of videos. Data analysis was conducted on response options, reasons, and confidence in responding. The results showed that online learning had an impact on the misconceptions about Chemistry Mathematics course participants with a range of 0-50% where the highest misconception identification results were found in the application of inverse trigonometric functions by 50%,while 0% misconceptions were obtained in the basic concepts of algebraic functions and conversion of rational equations into a partial fractions.
{"title":"Identifikasi Miskonsepsi Mahasiswa Pada Pembelajaran Daring Matematika Kimia Melalui Tes Diagnostik Three Tier Multiple Choice","authors":"Rina Elvia, Salastri Rohiat, S. Ginting","doi":"10.33394/hjkk.v9i2.4422","DOIUrl":"https://doi.org/10.33394/hjkk.v9i2.4422","url":null,"abstract":"The aim of this study is to determine the misconceptions of Chemistry Mathematics course participants during online learning in Chemistry Education Study Program, University of Bengkulu in the 2020/2021 academic year. This research starts with an online learning process for 4 meeting using Zoom meeting application and Google Classroom using synchronous and asynchronous methods. The method used to detect misconceptions is to provide a Three tier multiple choice diagnostic test consisting of multiple choice question, clear reasons in the form of an essay, and the level of confidence in answering and giving reasons. The tool used in this research is attest tool in the form of a diagnostic test and non-test tool in the form of an interview. Data collection techniques were conducted through test sheets in the form of a Google Forms application and short interviews about diagnostic tests in the form of videos. Data analysis was conducted on response options, reasons, and confidence in responding. The results showed that online learning had an impact on the misconceptions about Chemistry Mathematics course participants with a range of 0-50% where the highest misconception identification results were found in the application of inverse trigonometric functions by 50%,while 0% misconceptions were obtained in the basic concepts of algebraic functions and conversion of rational equations into a partial fractions.","PeriodicalId":346446,"journal":{"name":"Hydrogen: Jurnal Kependidikan Kimia","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124622143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andri Wahyu Wijayadi, Lina Arifah Fitriyah, Nur Hayati
Acid base properties can be easily observed based on the difference in color when using indicators. The use of indicators is very rare at the secondary school. Natural indicator are needed to support acid-base learning at the secondary school. This study aims to determine the effectiveness of local potency extract of jombang in the form of henna flowers as a natural indicator and the effectiveness of HVS paper and filter paper as indicator paper. Natural indicator paper was obtained by immersing HVS paper and filter paper in the extract of red and purple henna flowers using water solvent. The test result in acid and base solution showed that the red and purple henna flower extract had the same effectiveness as a natural indicator, as well the red and purple henna flower extract indicator paper made from HVS paper and filter paper.
{"title":"Pemanfaatan Potensi Lokal Jombang Berupa Bunga Pacar Air Sebagai Indikator Alami","authors":"Andri Wahyu Wijayadi, Lina Arifah Fitriyah, Nur Hayati","doi":"10.33394/hjkk.v8i2.3124","DOIUrl":"https://doi.org/10.33394/hjkk.v8i2.3124","url":null,"abstract":"Acid base properties can be easily observed based on the difference in color when using indicators. The use of indicators is very rare at the secondary school. Natural indicator are needed to support acid-base learning at the secondary school. This study aims to determine the effectiveness of local potency extract of jombang in the form of henna flowers as a natural indicator and the effectiveness of HVS paper and filter paper as indicator paper. Natural indicator paper was obtained by immersing HVS paper and filter paper in the extract of red and purple henna flowers using water solvent. The test result in acid and base solution showed that the red and purple henna flower extract had the same effectiveness as a natural indicator, as well the red and purple henna flower extract indicator paper made from HVS paper and filter paper.","PeriodicalId":346446,"journal":{"name":"Hydrogen: Jurnal Kependidikan Kimia","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126614817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The voltaic cell teaching materials used in high school are still in the form of textbooks that do not present multiple representations of chemistry, namely the macroscopic, submicroscopic, and symbolic levels. The three levels of chemical representation can be visualized using flipbook teaching materials so that students are expected to understand the voltaic cell material. Teaching materials are used to support the learning process. Current learning still uses conventional learning models that only focus on teachers. Constructivist-based active learning is needed because it involves students so that learning is more meaningful. One of the constructivist learning models is the guided inquiry learning model which includes observing, asking questions, compiling hypotheses, gathering information, testing hypotheses, and concluding. The purpose.of this development.is to.produce a proper guided inquiry-based flipbook teaching material. The flipbook teaching.materials were developed.using the Four-D model (define, .design, .develop,and.disseminate) but the disseminated stage was not carried out. Media and material validation was carried out by five chemistry lecturers. The legibility test was carried out by 50 high school alumni with a specialization in Science. The assessment uses a Likert scale accompanied by comments, suggestions from the validator, and audience. The data obtained from the analysis questionnaire to determine the feasibility level of the product using the percentage technique. The validation of the flipbook teaching materials development product in terms of material obtained an average score of 85.4%, validation in terms of media.obtained.an.average percentage of 85.5%, while the readability test results obtained.an.average.percentage of 87%. Based on the results.of material validation, media, and legibility tests, it can be concluded that the flipbook teaching materials guided inquiry-based voltaic cells are very suitable as a learning resource.
{"title":"Pengembangan Digital Flipbook untuk Menfasilitasi Kebutuhan Belajar Multiple Representation pada Materi Sel Volta","authors":"N. Setiawan, I. W. Dasna, M. Muchson","doi":"10.33394/hjkk.v8i2.3194","DOIUrl":"https://doi.org/10.33394/hjkk.v8i2.3194","url":null,"abstract":"The voltaic cell teaching materials used in high school are still in the form of textbooks that do not present multiple representations of chemistry, namely the macroscopic, submicroscopic, and symbolic levels. The three levels of chemical representation can be visualized using flipbook teaching materials so that students are expected to understand the voltaic cell material. Teaching materials are used to support the learning process. Current learning still uses conventional learning models that only focus on teachers. Constructivist-based active learning is needed because it involves students so that learning is more meaningful. One of the constructivist learning models is the guided inquiry learning model which includes observing, asking questions, compiling hypotheses, gathering information, testing hypotheses, and concluding. The purpose.of this development.is to.produce a proper guided inquiry-based flipbook teaching material. The flipbook teaching.materials were developed.using the Four-D model (define, .design, .develop,and.disseminate) but the disseminated stage was not carried out. Media and material validation was carried out by five chemistry lecturers. The legibility test was carried out by 50 high school alumni with a specialization in Science. The assessment uses a Likert scale accompanied by comments, suggestions from the validator, and audience. The data obtained from the analysis questionnaire to determine the feasibility level of the product using the percentage technique. The validation of the flipbook teaching materials development product in terms of material obtained an average score of 85.4%, validation in terms of media.obtained.an.average percentage of 85.5%, while the readability test results obtained.an.average.percentage of 87%. Based on the results.of material validation, media, and legibility tests, it can be concluded that the flipbook teaching materials guided inquiry-based voltaic cells are very suitable as a learning resource.","PeriodicalId":346446,"journal":{"name":"Hydrogen: Jurnal Kependidikan Kimia","volume":"394 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126747634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Risnita Vicky Listyarini, Puspita Ratna Susilawati, R. Cahyaningrum, Nely Tonapa
Pumpkin (Cucurbita moschata Durch) is one of the vegetable plants that are generally consumed as food. Pumpkin skin is a waste that has potential as a raw material for making bioplastics because it has pectin content. The characteristics of pectin that are gel become a reference in making bioplastics. Bioplastic synthesis consists of four steps, namely the making of pumpkin peel flour, pectin extraction, bioplastic synthesis, and bioplastic characterization. The experimental results show that pumpkin skin waste can be extracted with HCl solution and produce pectin in a ratio of0.1:10 grams (w/w). The results of FTIR spectra characterization showed that bioplastics included pectin which produced absorption of C = O carbonyl groups in 1645 - 1625 cm-1 and C-O stretch groups at 1101 - 1104 cm-1. Bioplastics produced have yellow characteristic. Pumpkin skin waste bioplastics are expected to be an alternative solution to the utilization of waste into products.
{"title":"Karakterisasi Bioplastik dari Pektin Kulit Labu Kuning (Cucurbita moschata Durch)","authors":"Risnita Vicky Listyarini, Puspita Ratna Susilawati, R. Cahyaningrum, Nely Tonapa","doi":"10.33394/hjkk.v8i1.2559","DOIUrl":"https://doi.org/10.33394/hjkk.v8i1.2559","url":null,"abstract":"Pumpkin (Cucurbita moschata Durch) is one of the vegetable plants that are generally consumed as food. Pumpkin skin is a waste that has potential as a raw material for making bioplastics because it has pectin content. The characteristics of pectin that are gel become a reference in making bioplastics. Bioplastic synthesis consists of four steps, namely the making of pumpkin peel flour, pectin extraction, bioplastic synthesis, and bioplastic characterization. The experimental results show that pumpkin skin waste can be extracted with HCl solution and produce pectin in a ratio of0.1:10 grams (w/w). The results of FTIR spectra characterization showed that bioplastics included pectin which produced absorption of C = O carbonyl groups in 1645 - 1625 cm-1 and C-O stretch groups at 1101 - 1104 cm-1. Bioplastics produced have yellow characteristic. Pumpkin skin waste bioplastics are expected to be an alternative solution to the utilization of waste into products.","PeriodicalId":346446,"journal":{"name":"Hydrogen: Jurnal Kependidikan Kimia","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115329039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The photorontgen process produces waste that is harmful to the environment because it contains silver ions that are toxic to living organisms. The silver content in photorontgent waste is 2000 mg / L, while the permissible threshold value for silver in aquatic is 0.1 - 1.0 mg / L, so the disposal of photorontgent waste into the waters will be dangerous. However, silver metal has high economic value so that silver metal separation from x-ray waste is required, in addition to reducing the environmental burden due to silver metal pollution, it is also expected to reuse the silver metal economically. The technique of separation that can be used is a supported liquid membrane (Supported Liquid Membrane, SLM). This technique has the advantage that its separation process is relatively easy because the extraction and stripping process takes place in one stage, the carrying solution as extractant is more stable in the supporting membrane and the amount of extractant required is small. This research studies the effect of waste dilution factors on the effieciency separation of silver from photorontgen waste. Separation was carried out at the optimum SLM condition by using combined carrier compound TBP and D2EHPA with a ratio of 0.25: 0.75, total concentration of 1 M in kerosene and 0.1 M HNO3 as stripping phase. Sample waste was diluted by a factor dilution 25, 50, 75 and 100 times. Measurement of metal content before and after separation is done with AAS. The results showed that the waste dilution factor influenced the efficiency of silver trasnpor through SLM. Percent of silver separation was obtained 21.33% in waste with 100 times dilution.
{"title":"Pemisahan Perak dari Limbah Fotorontgen dengan Teknik Membran Cair Berpendukung Menggunakan Pengemban Gabungan TBP dan D2EHPA","authors":"Yeti Kurniasih, Ahmadi Ahmadi, Baiq Asma Nufida","doi":"10.33394/hjkk.v8i1.2582","DOIUrl":"https://doi.org/10.33394/hjkk.v8i1.2582","url":null,"abstract":"The photorontgen process produces waste that is harmful to the environment because it contains silver ions that are toxic to living organisms. The silver content in photorontgent waste is 2000 mg / L, while the permissible threshold value for silver in aquatic is 0.1 - 1.0 mg / L, so the disposal of photorontgent waste into the waters will be dangerous. However, silver metal has high economic value so that silver metal separation from x-ray waste is required, in addition to reducing the environmental burden due to silver metal pollution, it is also expected to reuse the silver metal economically. The technique of separation that can be used is a supported liquid membrane (Supported Liquid Membrane, SLM). This technique has the advantage that its separation process is relatively easy because the extraction and stripping process takes place in one stage, the carrying solution as extractant is more stable in the supporting membrane and the amount of extractant required is small. This research studies the effect of waste dilution factors on the effieciency separation of silver from photorontgen waste. Separation was carried out at the optimum SLM condition by using combined carrier compound TBP and D2EHPA with a ratio of 0.25: 0.75, total concentration of 1 M in kerosene and 0.1 M HNO3 as stripping phase. Sample waste was diluted by a factor dilution 25, 50, 75 and 100 times. Measurement of metal content before and after separation is done with AAS. The results showed that the waste dilution factor influenced the efficiency of silver trasnpor through SLM. Percent of silver separation was obtained 21.33% in waste with 100 times dilution.","PeriodicalId":346446,"journal":{"name":"Hydrogen: Jurnal Kependidikan Kimia","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122241712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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