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All Journal Abdimas Jurnal Bahan Alam Terbarukan Sainteknol : Jurnal Sains dan Teknologi Jurnal Kimia dan Kemasan Chemistry in Education Indonesian Journal of Chemical Science Journal of Economic Education Jurnal Penelitian Pendidikan IPA (JPPIPA) ABDIMAS SILIWANGI Journal of Innovative Science Education International Journal of Active Learning Jurnal Pengabdian Masyarakat Khatulistiwa Jurnal Kimia dan Kemasan Jurnal Abdimas Kartika Wijayakusuma International Journal of Research Innovation and Entrepreneurship Proceeding of International Conference on Science, Education, and Technology Molekul: Jurnal Ilmiah Kimia al Kimiya : Jurnal Ilmu Kimia dan Terapan Indonesian Journal of Chemical Science Jurnal Abdimas International Journal of Active Learning
Cepi Kurniawan
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Agriculture, Biological Sciences & Forestry Arts Humanities Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Computer Science & IT Earth & Planetary Sciences Economics, Econometrics & Finance Education Environmental Science Languange, Linguistic, Communication & Media Law, Crime, Criminology & Criminal Justice Library & Information Science Materials Science & Nanotechnology Physics Public Health Social Sciences Other

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Pengelupasan Lapisan Grafit secara Elektrokimia dalam Suasana Asam Ramadhan, Dinar Alghifari; Kurniawan, Cepi; Mahatmanti, F Widhi
Indonesian Journal of Chemical Science Vol 8 No 2 (2019)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Abstrak Grafen merupakan alotrop karbon yang paling diminati untuk diteliti dalam bidang ilmu material dikarenakan sifat khasnya. Seiring dengan aplikasi grafen, eksplorasi metoda preparasi yang sederhana terus dikembangkan. Kendala utama dalam preparasi grafen diantaranya adalah kebutuhan bahan kimia yang banyak dan tidak ramah lingkungan. Dalam penelitian ini dilakukan preparasi grafen menggunakan metode pengelupasan elektrokimia dalam dalam elektrolit asam fosfat. Sumber grafit yang digunakan adalah pinsil 6B dan konsentrasi asam fosfat 1M. reaksi pengelupasan elektrokimia dilakukan dalam tabung reaksi berbentuk U. Hasil pengelupasan berbentuk serbuk hitam halus, di bawah pengamatan SEM serbuk ini terlihat sebagai lembaran. Hasil pengujian FTIR menunjukkan adanya vibrasi pada daerah 1564 cm-1 yang merupakan vibrasi karakteristik dari gugus C=C dari grafen. Abstract Graphene is the most desirable carbon allotrope for research in the field of material science due to its characteristics. Along with graphene applications, simple exploration of preparation methods continues to be developed. The main constraints in graphical preparation include the need for many chemicals and not being environmentally friendly. In this study graphene preparation was carried out using the electrochemical exfoliation method in phosphoric acid electrolytes. The graphite source used is pencil 6B and 1M phosphoric acid concentration. the electrochemical exfoliation reaction is carried out in a U-shaped test tube. The exfoliation is in the form of fine black powder, under the observation of SEM the powder is seen as a sheet. The FTIR test results showed a vibration in the area of 1564 cm-1 which is a characteristic vibration of the C = C group of graphene.
Analysis of Salt Hydrolysis Misconception With False Statements After Application of Guided Inquiry Assisted by E-Laboratory Instruction Zahrotil Umami, Min; Rubi’ah, Rubi’ah; Wardani, Sri; Kurniawan, Cepi
Journal of Innovative Science Education Vol 9 No 3 (2020): December 2020
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (238.767 KB) | DOI: 10.15294/jise.v8i3.35931

Abstract

Salt hydrolysis is a difficult chemical concept because it is microscopic and abstract. These properties can occur misconceptions. The misconception in this material is quite high and is spread across all concepts. Submission of this material with appropriate learning methods and models is expected to reduce student misconceptions. Therefore, it is necessary to conduct research aimed at studying the results of the analysis of salt hydrolysis misconceptions after the application of guided inquiry assisted by e-laboratory instructions. This research was conducted at Jekulo 1 High School in the 2018/2019 academic year with 104 research subjects. The method used in this research is quantitative description method. The results obtained showed that students' misconceptions of salt hydrolysis material after the application of guided inquiry assisted by e-laboratory instructions were still high. The results of misconception analysis on salt hydrolysis materials were 47.50%. Misconceptions regarding changes in color in a salt solution, ionic equilibrium in a salt solution, experimental experiments to predict the pH of a salt solution, the acidic acidic nature of a salt solution, and the pH of a suitable salt solution were 41.35%; 62.50%; 35.58%; 37.02%; and 61.06%.
Efforts to Increase Mathematical Logical Intelligence Through Development of Student Worksheets Based on Problem Based Learning Hardiyanti, Prahasti Cynthia; Wardani, Sri; Kurniawan, Cepi
Journal of Innovative Science Education Vol 9 No 3 (2020): December 2020
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (539.462 KB) | DOI: 10.15294/jise.v9i1.36846

Abstract

Chemistry is a subject that is closely related to learning that requires students to be active in problem solving. Because of this, a worksheet development is needed to support chemistry learning activities. This study aims to develop a Student Based Worksheet (LKPD) based on Problem Based Learning (PBL) hydrolysis material to improve mathematical logical intelligence. The quality of LKPD is measured by the criteria of validity, effectiveness, and practicality in the learning process. The development model used in this study is a 3D model (define, design and develop). Data analysis techniques using qualitative and quantitative tests. The product development validation was carried out by the validator of media experts and material experts, while the trial was conducted by 36 students of class XI IPA 5. The results of the validator analysis stated that the quality of learning material was included in the excellent category with a percentage of 93.77% of the material experts and 94.46% of media experts. The effectiveness of LKPD indicated an increase in mathematical logical intelligence of students with the achievement of N-gain of 0.56 in the medium category and classical completeness of 86.11%. Student responses to the practicality of using LKPD showed results of 77.78% which included in the very good category and 22.22% included in the good category. Based on the results obtained, it can be concluded that LKPD fulfills valid, effective, practical criteria, and can improve mathematical logical intelligence.
Preliminary Study of the Entrepreneurial Soul (Enterpreneur) of High School Students in Scientific Chemistry Learning with a Scientific Approach Karunia, Sabrina Dwie; Sumarni, Woro; Kurniawan, Cepi
Journal of Innovative Science Education Vol 9 No 3 (2020): December 2020
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (292.167 KB) | DOI: 10.15294/jise.v9i1.36847

Abstract

The results of this research study with descriptive qualitative methods aim to analyze the findings related to the entrepreneurial spirit of high school students. The subjects in this study were 69 students of class XI involving 2 state high schools in Semarang in the academic year 2018/2019. Data collection is done by observation, questionnaires, and documentation. The results showed that 64.71% in SMA X had an entrepreneurial spirit with strong criteria and 35.29% with very strong criteria. In state high school Y 2.86% have an entrepreneurial spirit with weak criteria, 65.71% strong criteria and 31.43% very strong criteria. High school students tend to have an entrepreneurial spirit with strong criteria. But after being analyzed, the lowest score on the entrepreneurial spirit is the aspect of confidence. Various supports in learning can be done to improve the quality of learning and produce students who have good self-confidence. Steps that need to be taken include improving the method or model of learning and using teaching materials that support the growth of the entrepreneurial spirit, especially in the aspect of self-confidence.
The Influence of Comic Media on Students' Concept Understanding on Chemical Bonding Materials Sinta, Ida Norma; Wardani, Sri; Kurniawan, Cepi
International Journal of Active Learning Vol 6, No 2 (2021): October 2021
Publisher : International Journal of Active Learning

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/ijal.v6i2.24498

Abstract

Research is motivated by the lack of understanding of students on chemical bonding material so that it has an impact on low learning outcomes and the use of effective learning media has not been utilized optimally. This study aims to determine the effect of comic media on students' understanding of concepts. This research is a mixed method. The research subjects of SMA Muhammadiyah 1 Sumenep class X IPA I and II were 39 students divided into 25 males and 14 females. Research data obtained and analyzed. The results showed that the average level of concept understanding with pretest and posttest was 12.09% and 69.6%, the percentage increase was 57.51%, the pretest normality test was 0.513 (> 0.05), then the data was normal, while the posttest was 0.368 (> 0.05) then the data is normal. The t-test results of the pretest and posttest are the tcount value (27,042)> ttable (1,686). The ttable value obtained with a confidence level of 95% and df 38, so it can be concluded that there is an effect of using comics media on the understanding of the concepts of Sumenep Private High School students on chemical bonds.
Steel Corrosion Protection with Water-Soluble Chitosan Inhibitor in 0,1 M HCl Solution Media Fitria, Reffy Ika; Mahatmanti, F. Widhi; Kurniawan, Cepi; Kusumastuti, Ella
Indonesian Journal of Chemical Science Vol 10 No 1 (2021)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/ijcs.v10i1.46015

Abstract

Corrosion in steel can reduce the steel quality, so it is necessary to have a corrosion inhibitor. Water-soluble chitosan can be an alternative as corrosion inhibitors. This study aims to determine the efficiency of water-soluble chitosan inhibitor (WSC) added to the corrosive HCl solution in the steel protection process, and to determine the maximum concentration of WSC as a steel corrosion protector. Water-soluble chitosan (WSC) has been prepared from chitosan by reacting with H2O2. The products obtained were used as corrosion protection inhibitors in steel in a corrosive solution of 0,1 M HCl. Chitosan and WSC were characterized by their physical properties and functional groups using FTIR and physical tests for yield, viscosity, molecular weight (BM),% DD, solubility, and water content. . The effectiveness of WSC in corrosion protection of steel in corrosive 0,1 M HCl solution was studied by weight loss and potentiodynamic polarization methods. The results obtained by chitosan were a viscosity of 1,4969 cP, BM 8,38 x 104,% DD 77,17%, 10,25% moisture content and 33,48% solubility. Water-soluble chitosan obtained yield 86.325%, viscosity 0,296 cP, BM 6,9 x 103,% DD 79,95%, water content 27,07% and 72,77% solubility. Inhibitor efficiency was found in WSC 2000 ppm and 0,1 M HCl, which was 68,15% EI (weight loss), while the potentiodynamic polarization method obtained an EI of 87,5%.
Cerium, Neodimium, and Lanthanum Leaching from Rare Earth Oxides (REO) using Hydrochloric Acid Aulia, Muhammad Azmi; Kurniawan, Cepi; Setyadji, Moch.
Indonesian Journal of Chemical Science Vol 10 No 2 (2021)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/ijcs.v10i2.45818

Abstract

Rare earth metal hydroxide (REOH) is a mixture of the elements lanthanide, yttrium, and scandium produced from the processing of monazite sand. This mixture has benefits in the modern technology industry, especially elements of Ce, La, and Nd. Separation of Ce, La, and Nd from the mixture has been carried out, but it has several drawbacks with the large use of chemicals that have an impact on the environment from the results of their processing waste and the length of time it takes, so the best solution is needed to overcome it. The perfect solution in the process of separating Ce, La, and Nd from REOH is leaching. Leaching is the extraction of acids with bases to form salt and water. This research begins with the REOH calcination process at a temperature of 1000⁰ C for 2 hours to evaporate volatiles and decompose the compounds. The results of calcination were leached using hydrochloric acid with a concentration variation of 0.3-1.2 M, temperature 30-75 ° C, a ratio of REO and solvent 1:5, and time variation of 5-20 minutes to optimize leaching efficiency. The results of leaching in residues were analyzed by XRF. The optimum leaching of the variation of the concentration of hydrochloric acid 1,2 M for 20 minutes resulted in the leaching efficiency of La and Nd respectively 33,297% dan 26,503%, and the leaching efficiency of Ce was 10,153% of the concentration of hydrochloric acid 0,9 M for 20 minutes. At a temperature variation of 75⁰ C and a time of 10 minutes, the leaching efficiency La and Ce were 55,87% dan 0,04%, respectively. The efficiency of Nd at 45⁰C for 20 minutes was 26,93%.
Pengaruh Project Based Learning Terintegrasi STEM Pada Pembelajaran Hidrolisis Garam Terhadap Keaktifan Siswa Nurfaijah, Siti; Sumarni, Woro; Sumarti, Sri Susilogati; Kurniawan, Cepi
Chemistry in Education Vol 10 No 2 (2021): Terbit bulan Oktober 2021
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/chemined.v10i2.42710

Abstract

“Pembelajaran aktif merupakan pendekatan pembelajaran yang lebih banyak melibatkan aktifitas siswa dalam mengakses berbagai informasi dan pengetahuan untuk dibahas dan dikaji dalam proses pembelajaran dikelas, sehingga mereka dapat meningkatkan pemahaman dan kompetensinya”. Studi literatur menunjukkan model pembelajaran yang dapat berpengaruh terhadap keaktifan siswa yaitu project based learning (PjBL) dengan STEM. Penelitian ini bertujuan menganalisis pengaruh project based learning terintegrasi STEM terhadap keaktifan siswa dan mengetahui seberapa besar pengaruh project based learning terintegrasi STEM terhadap keaktifan siswa. Jenis penelitian ini adalah penelitian Eksperimen Quasi dengan desain Control Group Design. Subyek penelitian adalah siswa kelas XI MIPA SMA Negeri di Cirebon sebanyak 32 siswa diambil dengan teknik purposive sampling. Pengumpulan data menggunakan instrumen lembar observasi yang telah divalidasi oleh ahli. Teknik analisis data yang digunakan dalam penelitian ini adalah uji T. Hasil analisis menunjukkan bahwa model Project Based Learning (PjBL) Terintegrasi STEM berpengaruh terhadap keaktifan siswa. Kata Kunci: Project Based Learning, STEM, keaktifan siswa.
Adsorpsi Logam Cr(VI) Dan Cu(II) Pada Tanah Dan Pengaruh Penambahan Pupuk Organik Wijayanti, Aris; Susatyo, Eko Budi; Sukarjo, Sukarjo; Kurniawan, Cepi
Indonesian Journal of Chemical Science Vol 7 No 3 (2018)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/ijcs.v7i3.22011

Abstract

Penyerapan ion logam Cu(II) dan Cr(VI) pada 3 jenis tanah yang berbeda yaitu jenis tanah Andisol yang berasal dari Magelang, tanah Inseptisol berasal dari Pati, dan jenis Tanah Grumosol berasal dari Demak. 2 gram masing-masing sampel tanah ditambah dengan aquades, CaCl2 0,01 M dan larutan logam Cu(II) dan Cr(VI) dari konsentrasi 20 ppm hingga 200 ppm. Isoterm Langmuir dan isoterm Freundlich digunakan untuk menganalisis model isoterm adsorpsi yang sesuai. Data adsorpsi ion logam Cu(II) dan Cr(VI) pada ketiga jenis tanah lebih sesuai dengan model isoterm Freundlich dibandingkan dengan isoterm Langmuir. Dari ketiga jenis tanah tersebut persamaaan Freundlich lebih sesuai untuk menggambarkan proses adsorpsinya, baik pada ion logam Cu(II) maupun Cr(VI). Persamaan isoterm Freundlich yang dihasilkan dapat digunakan untuk menghitung kapasitas adsorpsi. Kapasitas adsorpsi tanah untuk ion logam Cu(II) dan Cr(VI) meningkat seiring dengan meningkatnya pH, kapasitas tukar kation dan jumlah fraksi liat dalam tanah. Kapasitas adsorpsi ion logam Cu(II) dan Cr(VI) tertinggi yaitu pada jenis tanah Grumosol kemudian Inseptisol dan terendah pada jenis tanah Andisol. Adsorpsi ion logam Cu(II) dan Cr(VI) pada tanah Andisol yang telah ditambahkan pupuk organik lebih mengikuti model persamaan Langmuir. Penambahan pupuk kandang dapat mempengaruhi kapasitas adsorpsi, dengan penambahan pupuk kandang kapasitas adsorpsi ion logam Cu(II) dan Cr(VI) pada tanah Andisol meningkat.
Optimasi Epoksidasi Fatty Acid Methyl Esters (FAME) Berbasis Palm Olein sebagai Aditif Pemlastis Cat Irawati, Irawati; Kurniawan, Cepi; Harjono, Harjono
Indonesian Journal of Chemical Science Vol 8 No 1 (2019)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/ijcs.v8i1.24005

Abstract

Telah dilakukan penelitian tentang optimasi epoksidasi fatty acid methyl ester (FAME) berbasis palm olein sebagai aditif pemlastis cat. Penelitian ini bertujuan untuk mengetahui hasil optimum senyawa epoksi yang telah disintesis berdasarkan parameter bilangan oksiran dan bilangan iod. Sintesis senyawa epoksi dilakukan menggunakan FAME, asam asetat, katalis amberlit IR-120, asam peroksida 50%, dan pelarut toluen pada suhu 70 oC dan kecepatan pengadukan 100 rpm. Pada optimasi waktu 1, 3, dan 5 jam didapat waktu optimum sintesis pada 3 jam dengan nilai bilangan oksiran sebesar 4,17% dan bilangan iod sebesar 7,66%. Pada optimasi rasio dan penambahan katalis, didapat optimum sintesis pada rasio 1:2 dan penambahan katalis 3 gram dengan bilangan oksiran 4,26% dan bilangan iod sebesar 5,42%. Konversi sebesar 90% dan selektivitas sebesar 70%. Hasil karakterisasi menggunakan FT-IR diketahui bahwa senyawa hasil sintesis diduga mengandung senyawa epoksi. Analisis data menggunakan RSM menunjukkan korelasi yang tinggi antara variable bebas dengan respon berupa variable terikat sebesar 96%.
Co-Authors - Jumaeri Agung Tri Prasetya Alvin Nur Zahro Annisa Lestari Aris Wijayanti Arma Yoga Atika Wijaya Aulia, Muhammad Azmi Aulia, Syiva Zakia Azzahra, Elvara Siti Bahron, Hadariah Budi Astuti Didik Prasetyoko Dimas Gilang Ramadhani, Dimas Gilang Doni Setiawan Edy Cahyono Eko Budi Susatyo Ella Kusumastuti, Ella Endang Susilaningsih F Widhi Mahatmanti Fitria, Reffy Ika Haq, Ismi Arinal Harjito - Harjito Harjito Harjono Harjono Harjono Herlina Dewi, Siti Hilda, Shinta Ida Norma Sinta, Ida Norma Irawati Irawati Ladjidji, Delfris Ariya Pratama Mahfudz, Johar Massora, Kris Maylia Rosanti, Yuan Moch. Setyadji Mohammad Alauhdin, Mohammad Murbangun Nuswowati Nisa, Hoirun Nugraha, Rizki Nuni Widiarti Nurfaijah, Siti Nuril Huda Oktaviyanti, Dita Try Prahasti Cynthia Hardiyanti, Prahasti Cynthia Pramestia, Rena Aliya Prasetyo, Ridho Qonita, Ulya Rahmi Fauziah, Rahmi Rakhmawati, Indri Ramadhan, Dinar Alghifari Rohmah, Rojja Maysa Rosanti, Yuan Maylia Rubi’ah, Rubi’ah Sabatinie, Indrie Sabrina Dwie Karunia, Sabrina Dwie Sri Haryani Sri Kadarwati Sri Nurhayati Sri Susilogati Sumarti SRI WARDANI Sucihatiningsih Dian Wisika Prajanti Sudarmin Sudarmin Sukarjo Sukarjo, Sukarjo Sulistyani, Martin Sulistyaningrum, Devitri Sungkowo Sungkowo, Sungkowo Suprapto, Surapto Sutikno Madnasri Syaifariz, Akbar Teguh Budiyanto, Teguh Tri Prasetya, Agung Wara Dyah Pita Rengga Warlan Sugiyo Widastra, Holifiled Woro Sumarni Yulianto, Agung Ade Yusuf Nugi Nugraha Zahrotil Umami, Min