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All Journal Jurnal Pendidikan dan Pembelajaran Kimia (JPPK) JURNAL PENELITIAN SAINTIKA Jurnal Pendidikan Kimia (JPKim) Pendas : Jurnah Ilmiah Pendidikan Dasar Jurnal Inovasi Pembelajaran Kimia (Journal Of Innovation in Chemistry Education) CHEDS: Journal of Chemistry, Education, and Science Makara Journal of Science
Marham Sitorus
Department of Chemistry, Faculty of Mathematics and Natural Sciences, Medan State University
Biochemistry, Genetics & Molecular Biology Chemistry Computer Science & IT Decision Sciences, Operations Research & Management Education Environmental Science Materials Science & Nanotechnology Social Sciences Other

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OPTIMASI SUHU WAKTU DAN JUMLAH DEHIDRATOR P2O5 UNTUK MEDEHIDRASI RISINOLEAT CASTOR OIL MENJADI ASAM LINOLEAT TERKONJUGASI Sitorus, Marham; Sutiani, Ani
JURNAL PENELITIAN SAINTIKA Vol 14, No 2 (2013): SEPTEMBER 2013
Publisher : JURNAL PENELITIAN SAINTIKA

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Abstract

Telah dilakukan optimasi suhu,waktu dan jumlah dehidrator P2O5 optimal untuk mendehidrasi castor oil menjadi Asam Linoleat Terkonjugasi. Reaksi dilakukan dengan cara refluks dengan memvariasi salah satu faktor dengan dua faktor yang lain tetap. Analisis hasil dilakukan dengan kombinasi alat GC dan GC-MS yang dibandingkan dengan standar maka kondisi optimal adalah: suhu 200oC, waktu 4 jam dan 3%(b/b) P2O5. Konversi (yield) yang diperoleh pada suhu optimal adalah 97,94%.
OPTIMASI SUHU WAKTU DAN JUMLAH DEHIDRATOR P20s UNTUK MEDEHIDRASI RISINOLEAT CASTOR OIL MENJADI ASAM LINOLEAT TERKONJUGASI Sitorus, Marham; Sutiani, Ani
JURNAL PENELITIAN SAINTIKA Vol 13, No 2 (2013): SEPTEMBER 2013
Publisher : JURNAL PENELITIAN SAINTIKA

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Abstract

Telah dilakukan optimasi suhu,waktu dan jumlah dehidratorP20s optimal untuk mendehidrasi castor oil menjadi Asam LinoleatTerkonjugasi. Reaksi dilakukan dengan cara refluks dengan memvariasisalah satu faktor dengan dua faktor yang lain tetap. Analisis hasil dilakukandengan kombinasi alat GC dan GC-MS yang dibandingkan dengan standarmaka kondisi optimal adalah: suhu 200°C, waktu 4 jam dan 3%(b/b) P20s.Konversi (yield) yang diperoleh pada suhu optimal adalah 97,94% ...
PEMURNIAN ASAM LINOLEAT TERKONJUGASI HASIL SINTESA DARI RISINOLEAT CASTOR OIL DENGAN KROMATOGRAFI KOLOM SILIKAGEL PERAK NITRAT Sitorus, Marham; Nainggolan, Bajoka
JURNAL PENELITIAN SAINTIKA Vol 14, No 1 (2014): Maret 2014
Publisher : JURNAL PENELITIAN SAINTIKA

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Abstract

Conjugated Linoleic acid (CLA) was sepereted by usingcolomn chromatography with silicagel – AgNO3 as stationaryphase. Seperation based on the differences reversibility ofcoordination bond between double bond and silver ion. Theindreasing number of double bond and trans isomers morestrongly the molecule is retained. Gradien elution was carried outby various n-hexane (H) and Acetone (A) (v/a) e. g: 97.5/2.5; 95/5;90/10; 80/20; 70/30 and 60/40 in 8 vial x 2.5 mL. Each of fractionwas analyzd by using GC,FTIR, UV and GC-MS and It’s comparewith authentic CLA standard and the best was ratio (v/v) of eluen(H/A) 95/5. The composition of product ratio of CLA/linoleic was0,85 : 1 or 77.6 % compared to the authentic standar 1.45/1. 
Modeling of Benzimidazole Derivatives as Antimalarial Agents using QSAR Analysis Hadanu, Ruslin; Sitorus, Marham
Makara Journal of Science Vol. 28, No. 3
Publisher : UI Scholars Hub

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In this study, quantitative structure–activity relationship (QSAR) analysis was conducted on 20 homologous compounds of benzimidazole derivatives. The structures of the benzimidazole derivatives were optimized using the semiempirical Parameterized Model 3 method of HyperChem for Windows 8.0 to obtain 14 descriptors. Then, multiple linear regression (MLR) analysis was performed using the backward method. The results of the MLR analysis obtained four new QSAR equation models. Based on statistical criteria, model 1 was determined as the best QSAR equation model in predicting the theoretical IC50 values of the new benzimidazole derivatives. As many as 20 new compounds of benzimidazole derivatives were modeled, of which 13 new compounds (23, 24, 25, 26, 27, 28, 29, 30, 31, 37, 38, 39, and 40 compounds) were recommended for synthesis in the laboratory because these compounds of benzimidazole derivatives havethey theoretically had higher antimalarial activity than chloroquine
Development of E-LKPD Based on Problem Based Learning (PBL) Using Liveworksheet Website on Acid Base Material in High School Putri, Salsabilla; Sitorus, Marham
Jurnal Pendidikan dan Pembelajaran Kimia Vol 13, No 3 (2024): Jurnal Pendidikan dan Pembelajaran Kimia
Publisher : Universitas Lampung

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Abstract

The problem of chemistry learning in high school during learning is that students find it difficult to understand the material and determine problem solving. Therefore, teaching materials are needed to overcome these problems. The purpose of this study is to produce E-LKPD based on Problem Based Learning using the Liveworksheet website on acid-base material in high school that is valid and practical for use by teachers in online learning activities. The type of research used is R&D (Research and Development) using the ADDIE model, namely (Analysis, Design, Development, Implementation, and Evaluation). The data analysis technique in this study uses qualitative descriptive and quantitative descriptive analysis techniques. This was obtained from the results of the analysis of the expert validation instrument material 78% and media 79% with a valid category, and the results of student responses obtained a practical percentage of 87%, while the results of the N-Gain trial were 72.29% with high criteria. Based on the results of the research and discussion, it can be concluded that the development of E-LKPD based on Problem Based Learning using the Liveworksheet website on acid-base material in high school is valid and very feasible to be used in learning activities.Keywords: Development, E-LKPD, PBL, Liveworksheet, Acid BaseDOI: 10.23960/jppk.v13i3.30472                             
The Influence of Problem Based Learning Weblog on Students Motivation and Learning Outcomes on Thermochemical Marpaung, Ester Muliana; Sitorus, Marham
Jurnal Inovasi Pembelajaran Kimia (Journal of Innovation in Chemistry Education) Vol. 6 No. 1 (2024): APRIL 2024 EDITION
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/jipk.v6i1.57248

Abstract

This research aims to determine the influence of weblog media using the problem-based learning model on student motivation and learning outcomes on thermochemical material. This research was conducted at SMAN 1 Percut Sei Tuan in the 2023/2024 academic year. Sample determination was carried out using a purposive sampling technique. The sample consisted of 2 classes, namely class XI-Matlanko 2 as an experimental class (30 students) which was taught using Weblog media and class The instruments used are test instruments to measure learning outcomes and non-test instruments to measure learning motivation. The results of this research indicate that there is an influence of using a weblog using a problem-based learning model on student learning motivation by testing the sig hypothesis. 0.00 < α (0.05) and there is also an influence of using a weblog using the problem-based learning model on student learning motivation with hypothesis testing sig. 0.00 < α (0.05). Apart from that, there is a correlation between learning motivation and student learning outcomes who are taught using weblog media using the problem-based learning model with sig. 0.00 < α (0.05) and Pearson correlation 0.953 with the high category.
The Effect of E-Module on Activity and Learning Outcomes on Electrolyte and Nonelectrolyte Solutions Damanik, Nova; Riris, Ida Duma; Sitorus, Marham; Sihombing, Junifa Layla; Syafriani, Dewi
Jurnal Inovasi Pembelajaran Kimia (Journal of Innovation in Chemistry Education) Vol. 5 No. 2 (2023): OCTOBER 2023 EDITION
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/jipk.v5i2.54922

Abstract

This research aims to determine activities, learning outcomes and the correlation between activities and student learning outcomes taught using the Project Based Learning (PjBL) learning model assisted by e-modules for class X SMA on electrolyte and non-electrolyte solutions. The population in this study were students of class This research uses test and non-test instruments in the form of student learning activity observation sheets which have been tested and are valid. The data obtained were tested for normality and homogeneity. Based on the results of data processing that has been analyzed, there are learning outcome values tcount = 9.714 and ttable = 1.66, the activity obtained is tcount = 6.069 and ttable = 1.66. Where tcount>ttable shows that Ha is accepted and H0 is rejected, so it can be concluded that there is an influence of the Project Based Learning (PjBL) learning model assisted by e-modules for class X SMA on electrolyte and non-electrolyte solutions. The correlation test was carried out to determine the significant correlation between activities and student learning outcomes. The research results show that rcount > rtable (0.929 > 0.329) so H0 is rejected. Thus, there is a significant correlation between activities and student learning outcomes assisted by e-modules for class X SMA on electrolyte and non-electrolyte solutions.
Effectiveness of sulfuric acid and hydrochloric acid catalysts in the esterification of frankincense cinnamic acid with ethanol and methanol Sitorus, Marham; Suyanti, Retno Dwi; Jahro, Iis Siti; Siahaan, Suria Bersinar; Saragih, Innovayani; Sitorus, Francisca T. A
Jurnal Pendidikan Kimia Vol. 16 No. 1 (2024): April
Publisher : Pascasarjana Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/jpkim.v16i1.53231

Abstract

This research aims to compare the effectiveness of sulfuric acid and hydrochloric acid catalysts in the esterification of frankincense cinnamic acid (STYRAX paraleoncomud PERK). Esterification of sulfuric acid catalyst is carried out with ethanol and for hydrochloric acid catalyst with methanol. Esterification was carried out by refluxing a mixture of 1:20 cinnamic acid - ethanol and methanol, with 3 mL of each catalyst at a temperature of 60oC for one hour. The results were rinsed with 3 x 50 mL distilled water and dried with anhydrous sodium sulfate. The results were filtered and verified for functional groups using FTIR and composition analysis using GC “ MS. The results of FTIR interpretation show a decrease in absorption intensity (-OH) at 3500 cm-1 as a functional group that reacts compared to the ester results as an indication of the ongoing esterification reaction. The resulting ethyl cinnamate has a high conversion of 84.42%. Methyl cinnamate also has a distinctive ester aroma but is clearer and based on GC-MS, the content of methyl cinnamate is relatively low, namely 34.40%, the remaining cinnamic acid is 37.28%, and various side products of 28.32%. Thus, the catalyst that provides better conversion is sulfuric acid, but it requires further purification by examining the appropriate absorbent and bleaching agent. The brown color of the ester product catalyzed by sulfuric acid is thought to occur due to the oxidation of the cinnamic acid double bond by the catalyst.
SINTESIS METIL SINAMAT DENGAN REAKSI ESTERIFIKASI ANTARA ASAM SINAMAT DALAM GETAH KEMENYAN TOBA (STYRAX PARALLEONCOMUD PERK) DAN METANOL Siahaan, Suria Bersinar; Sitorus, Marham
CHEDS: Journal of Chemistry, Education, and Science Vol 7, No 2 (2023)
Publisher : Universitas Islam Sumatera Utara

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30743/cheds.v7i2.8129

Abstract

Pada penelitian ini dilakukan sintesis metil sinamat dari asam sinamat kemenyan Toba. Asam sinamat diekstraksi dari lateks benzoin Toba kemudian dianalisis dengan FTIR. Ekstrak asam sinamat sebanyak 82,6% disintesis menjadi metil sinamat melalui reaksi esterifikasi dengan katalis HCl, kemudian produk esterifikasi yang dihasilkan dikarakterisasi menggunakan instrumen FTIR dan GC-MS. Hasil analisis FTIR asam sinamat menunjukkan bahwa ikatan O-H, C=C, C=O, C-O (asam karboksilat) dan C-H sesuai dengan gugus fungsi asam sinamat. Analisis FTIR terhadap metil sinamat menunjukkan bahwa produk tersebut merupakan senyawa ester dengan adanya ikatan ester C-O dan C=O yang didukung oleh aroma produk yang harum seperti aroma anggur. Hasil analisis GC-MS terhadap metil sinamat menunjukkan kandungan metil sinamat sebesar 34,4% dengan nilai m/e sebesar 162 sesuai dengan m/e metil sinamat dengan tingkat kemiripan sebesar 93%.
Development of E-LKPD Based on Problem Based Learning (PBL) Using Liveworksheet Website on Acid Base Material in High School Putri, Salsabilla; Sitorus, Marham
Jurnal Pendidikan dan Pembelajaran Kimia Vol 13, No 3 (2024): Jurnal Pendidikan dan Pembelajaran Kimia
Publisher : Universitas Lampung

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

Abstract

The problem of chemistry learning in high school during learning is that students find it difficult to understand the material and determine problem solving. Therefore, teaching materials are needed to overcome these problems. The purpose of this study is to produce E-LKPD based on Problem Based Learning using the Liveworksheet website on acid-base material in high school that is valid and practical for use by teachers in online learning activities. The type of research used is R&D (Research and Development) using the ADDIE model, namely (Analysis, Design, Development, Implementation, and Evaluation). The data analysis technique in this study uses qualitative descriptive and quantitative descriptive analysis techniques. This was obtained from the results of the analysis of the expert validation instrument material 78% and media 79% with a valid category, and the results of student responses obtained a practical percentage of 87%, while the results of the N-Gain trial were 72.29% with high criteria. Based on the results of the research and discussion, it can be concluded that the development of E-LKPD based on Problem Based Learning using the Liveworksheet website on acid-base material in high school is valid and very feasible to be used in learning activities.Keywords: Development, E-LKPD, PBL, Liveworksheet, Acid BaseDOI: 10.23960/jppk.v13i3.30472                             
Co-Authors Ani Sutiani Bajoka Nainggolan Damanik, Nova Daulay, Rabiah Dewi Syafriani, Dewi Ginting, Elfrida Ida Duma Riris Iis Siti Jahro Junifa Layla Sihombing, Junifa Layla lespiani, ika Marpaung, Ester Muliana Putri, Salsabilla Ramlan Silaban Retno Dwi Suyanti Ruslin Hadanu Saragih, Innovayani Siahaan, Suria Bersinar Sitorus, Francisca T. A