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All Journal INDONESIAN JOURNAL OF APPLIED PHYSICS Walisongo Journal of Chemistry Indonesian Journal of Chemical Science and Technology CHEDS: Journal of Chemistry, Education, and Science
Ramadhan, Dwi Sapri
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Astronomy Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Education Energy Materials Science & Nanotechnology Physics

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Effect of Electrode Type and Current Strength on the Mass of Substance Reduced at the Cathode in the Electrolysis Process Fahmi, Jam'an; Ramadhan, Dwi Sapri; Wardana, Dian; Safitri, Wulan Dwi; Zubir, Moondra; Siregar, Nurdin; Manullang, Riska Greselia; Sagala, Novitri Yolanda; Br Sipahutar, Desy Meriani
Indonesian Journal of Chemical Science and Technology (IJCST) Vol. 8 No. 2 (2025): JULY 2025
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/ijcst.v8i2.70607

Abstract

This study investigates the effect of electrode type and current strength on the mass of hydrogen gas produced at the cathode during the electrolysis of sodium chloride solution. A simulation based on Faraday’s law was conducted using three electrode materials—carbon, copper, and zinc—under controlled current settings of 0.10 A, 0.20 A, and 0.30 A for a fixed electrolysis duration of 30 minutes. Current efficiency values were assigned to each electrode to model realistic performance differences, with copper exhibiting the highest efficiency, followed by zinc and carbon. The results show that increasing the current leads to a linear rise in the mass of hydrogen produced for all electrode types, confirming the proportional relationship between electric charge and cathodic reduction predicted by Faraday’s law. Additionally, copper electrodes produced the highest hydrogen yield at all current levels, while carbon generated the lowest, indicating that electrode characteristics influence electrochemical efficiency. Overall, the findings demonstrate that current strength is the dominant factor determining the mass of reduced species at the cathode, whereas electrode material provides a secondary yet significant contribution to electrolysis effectiveness.
Effect of Sugar Addition on the Electric Current Strength of Mixtures with Vinegar, Lime Extract, Coffee, Salt Solution, and 70% Alcohol Wardana, Dian; Ramadhan, Dwi Sapri; Fahmi, Jam'an; Safitri, Wulan Dwi; Siregar, Ida Cathy Everyanti; Silalahi, Sarina Septiani; Zubir, Moondra; Siregar, Nurdin
Indonesian Journal of Chemical Science and Technology (IJCST) Vol. 8 No. 2 (2025): JULY 2025
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/ijcst.v8i2.70611

Abstract

This study aims to examine the electric current strength of sugar mixed with various electrolyte and non-electrolyte solutions. The research employed an experimental approach using vinegar, lime extract, coffee solution, salt solution, and 70% alcohol combined with sugar solutions. A battery system and a digital multimeter were utilized to measure the resulting current in each mixture. The findings indicate that increasing the amount of sugar leads to a reduction in current strength, whereas decreasing the sugar content results in a higher current output.
Influence of EM4 Inoculum on Biogas Yield and pH Dynamics in Lettuce and Cabbage Waste Fermentation Ramadhan, Dwi Sapri; Safitri, Wulan Dwi; Wardana, Dian; Fahmi, Jam'an; Zubir, Moondra; Andini, Ayu; Simamora, Elisabeth; Limbong, Julian; Sihotang, Pelita; Husna, Wiki Nadia; Siregar, Nurdin
Indonesian Journal of Chemical Science and Technology (IJCST) Vol. 8 No. 2 (2025): JULY 2025
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/ijcst.v8i2.70612

Abstract

Biogas production from vegetable waste offers a practical pathway for reducing organic residues and supporting small-scale renewable energy systems. This study investigates the influence of EM4 inoculum on gas accumulation and pH dynamics during an 8-day batch fermentation of lettuce and cabbage waste. Four reactors were prepared containing 200 g vegetable waste and 200 mL water with or without 30 g EM4. Gas accumulation was quantified by balloon circumference at day 2, day 4, day 6 and day 8 and converted to volume using geometric calculations. Lettuce generated the highest peak volumes with maximum values exceeding 330 cm³ while cabbage produced less than 60 cm³ under comparable conditions. pH trajectories showed that cabbage plus water decreased from pH 7 to pH 6 whereas lettuce plus water increased from pH 7 to pH 8. Reactors containing EM4 stabilised at pH 6 throughout the fermentation indicating inoculum-supported buffering. These results demonstrate that substrate characteristics strongly influence early-stage gas formation and that EM4 moderates pH fluctuations even under uncontrolled ambient conditions. The findings provide initial evidence that lettuce is a more degradable feedstock than cabbage and emphasise pH regulation as a key requirement for improving methane-oriented biogas performance in simple batch systems.
Effect of Organic and Inorganic Compounds on the Conductivity of Salt Solutions Safitri, Wulan Dwi; Wardana, Dian; Ramadhan, Dwi Sapri; Fahmi, Jam'an; Zubir, Moondra; Purba, Sunita Karin; Puandra, Esti Miska; Siregar, Nurdin
Indonesian Journal of Chemical Science and Technology (IJCST) Vol. 8 No. 2 (2025): JULY 2025
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/ijcst.v8i2.70635

Abstract

This study examines the effects of selected organic and inorganic compounds on the electrical conductivity of salt solutions. Organic substances (sugar, coffee, tea, and a surfactant-based cleaner) and inorganic additives (ammonium chloride in cough medicine, povidone–iodine, and carbonated beverage) were mixed with salt solutions at varying concentrations to evaluate their influence on ion availability and mobility. The results show that conductivity increases proportionally with salt concentration, confirming that ion content is the primary factor governing charge transport. Inorganic ionic additives significantly enhanced conductivity by releasing additional ions into the solution, whereas non-ionic organic compounds consistently reduced conductivity at low salt levels by diluting ionic species and hindering ion mobility. Conductivity in organic mixtures increased only when salt concentration became dominant. These findings highlight the contrasting mechanisms of organic and inorganic additives in modifying electrolyte behavior and provide useful insight for chemistry education and simple electrochemical analysis.
Analysis of the Effect of Varying Concentrations of Strong Acids (HCl) and Weak Acids (CH3COOH) with Mixing of Bases (Detergent) on the Temperature Increase of the Reaction Results Fahmi, Jam'an; Ramadhan, Dwi Sapri; Wardana, Dian; Safitri, Wulan Dwi; Zubir, Moondra; Siregar, Nurdin; Br Sebanyang, Resi Mai Linda Etaminta; Br Napitupuli, Monika Shinta Kasih; Lumbantoruan, Sifra H.R
Indonesian Journal of Chemical Science and Technology (IJCST) Vol. 8 No. 2 (2025): JULY 2025
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/ijcst.v8i2.70670

Abstract

Neutralization reactions between acids and bases are generally exothermic processes that release heat because of water formation from H⁺ and OH⁻ ions. This study aims to investigate the effect of varying concentrations of a strong acid (HCl) and a weak acid (CH₃COOH) on the temperature increase produced when these acids are reacted with a detergent-based alkaline material. Experiments were conducted using three acid concentrations—0.1 M, 0.3 M, and 0.5 M—each mixed with 3 g, 5 g, and 7 g of detergent in a reaction volume of 25 mL. The results indicate that increasing acid concentration correlates positively with greater temperature elevation. The largest temperature increase, 5.7°C, was observed in the reaction between 0.5 M HCl and 7 g of detergent, whereas the lowest increase, 0.5°C, occurred in the reaction between 0.1 M CH₃COOH and 3 g of detergent. Differences in ionization strength between strong and weak acids significantly influence the amount of heat released during neutralization. These findings demonstrate that both acid strength and base mass play important roles in determining the exothermic energy output of acid–base reactions.
PENERAPAN MEDIA PEMBELAJARAN BERBASIS WEBSITE MENGGUNAKAN MODEL KOOPERATIF TIPE SCRAMBLE PADA MATERI HIDROLISIS GARAM Safitri, Wulan Dwi; Eddiyanto, Eddiyanto; Wardana, Dian; Ramadhan, Dwi Sapri; Fahmi, Jam'an
CHEDS: Journal of Chemistry, Education, and Science Vol 9, No 2 (2025)
Publisher : Universitas Islam Sumatera Utara

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30743/cheds.v9i2.11838

Abstract

Fokus penelitian ini adalah untuk menentukan peningkatan hasil belajar siswa di kelas eksperimen setelah diajar menggunakan media pembelajaran berbasis web dengan model kooperatif tipe scramble pada materi hidrolisis garam. Instrumen yang digunakan adalah 20 pertanyaan objektif. Dari hasil analisis, rata-rata peningkatan siswa kelas eksperimen adalah 0,7414 (kategori tinggi) dan di kelas kontrol adalah 0,5881 (kategori sedang). Berdasarkan hasil uji hipotesis dengan uji t sisi kanan, ditemukan bahwa t hitung lebih besar dari t tabel atau 8,064 2,0021 dengan tingkat signifikansi α = 0,05, sehingga Ha diterima, sehingga peningkatan hasil belajar di kelas yang diajar menggunakan media pembelajaran berbasis web lebih tinggi daripada peningkatan hasil belajar di kelas yang diajar tanpa menggunakan media pembelajaran berbasis web (konvensional).
COMPARATIVE GC–MS CHARACTERIZATION AND PHYSICOCHEMICAL EVALUATION OF Citrus hystrix DC. ESSENTIAL OILS FROM DIFFERENT PLANT PARTS Ramadhan, Dwi Sapri; Warsito, Warsito; Azzahra, Vina Octavia; Wardana, Dian; Fahmi, Jam’an; Safitri, Wulan Dwi
Walisongo Journal of Chemistry Vol. 8 No. 2 (2025): Walisongo Journal of Chemistry
Publisher : Department of Chemistry Faculty of Science and Technology UIN Walisongo

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21580/wjc.v8i2.28063

Abstract

Essential oils from Citrus hystrix DC. are known for their rich bioactive composition, particularly citronellal, which has extensive applications in the fragrance and pharmaceutical industries. However, comparative studies on the chemical and physicochemical properties of oils extracted from different plant parts remain limited. This study investigated essential oils obtained by steam distillation from leaves (LEO), twigs (TEO), and a leaf–twig mixture (LTMEO). The oils were characterized using GC–MS and FTIR analyses, alongside measurements of density, refractive index, and yield. LTMEO yielded a yellow, aromatic oil with a density of 0.856 g/mL, a refractive index of 1.439, and a yield of 0.60%, consistent with the quality requirements of SNI 9231:2023. GC–MS profiling identified citronellal as the dominant compound, with concentrations of 83.88% in LEO, 69.88% in LTMEO, and 46.47% in TEO. FTIR spectra confirmed the presence of aldehyde functional groups, consistent with the high citronellal content. Minor constituents such as linalool (5.24–8.91%), isopulegol (0.47–2.95%), β-citronellol (2.03–12.22%), and citronellyl acetate (4.28–6.48%) were also detected, potentially affecting citronellal isolation. Overall, the findings highlight C. hystrix DC. leaves as the most promising source of citronellal for industrial applications.
Chemical Composition and Quality Parameters of Citronella (Cymbopogon nardus) Essential Oil Based on GC–MS and Physicochemical Analysis Ramadhan, Dwi Sapri; Warsito; Silvianti, Risna; Cahayo, Maf'ud; Azzahra, Vina Octavia
Indonesian Journal of Chemical Science and Technology (IJCST) Vol. 9 No. 1 (2026): JANUARY 2026
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/ijcst.v9i1.72493

Abstract

Citronella (Cymbopogon nardus (L.) Rendle) essential oil is widely utilized in the perfume, cosmetic, and pharmaceutical industries, primarily due to its high content of citronellal, geraniol, and citronellol. This study aimed to evaluate the chemical composition and quality parameters of citronella essential oil using gas chromatography–mass spectrometry (GC–MS) and physicochemical analysis. The oil sample was obtained by steam distillation of fresh leaves and subsequently characterized in terms of specific gravity, refractive index, optical rotation, and flash point, while the chemical composition was determined based on GC–MS chromatogram peak areas. The physicochemical analysis showed a specific gravity of 0.894, refractive index of 1.477, optical rotation of −6.59°, and a flash point above 80 °C, indicating compliance with quality standards for citronella essential oil. GC–MS analysis identified 21 compounds, with trans-geraniol (70.65%), geranyl acetate (7.70%), β-citronellol (3.17%), and citronellal (1.78%) as the major constituents. These findings confirm that steam-distilled citronella essential oil exhibits good quality and a chemical profile that supports its potential for essential oil-based industrial applications.
EDLC Type Supercapacitor Electrode Based on Banana Peels Activated Carbon Rahmah, Alfiatur; Zainollah, Ahmad; Fitriani, Novi Artika; Ramadhan, Dwi Sapri; Cahayo, Maf'ud; Masruroh, Masruroh
INDONESIAN JOURNAL OF APPLIED PHYSICS Vol 7, No 1 (2017): April
Publisher : Department of Physics, Sebelas Maret University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.13057/ijap.v7i1.1414

Abstract

The objective of this research is to observe the influence of surface area and porosity of banana peels activated carbon on the specific capacitance value as EDLC type supercapacitor electrode. Banana peels have been carbonated at temperature of 600ºC and activated using KOH with concentrations of 5%, 15%, 25% and 35% at temperature of 700ºC. The activated carbon banana peels mixed with PVAc (Polyvinyl acetat), added with aquades and compressed on pressure of 80 kN. The specific capacitance has been carried out using galvanostatic method with KOH 30% as electrolyte solution. Pore size of membrane activated carbon was observed using Scanning Electron Microscopy (SEM) and Brunnuaer-Emmet-Teller (BET) method for surface area of activated carbon. The result shows that the optimum value at activation using KOH 25% with large surface area 540,454 m2/g, porosity 17,89 µm and specific capacitances of 72,93 F/g. The increase of large surface area and porosity activated carbon has affected to specific capacitance value, so activated carbon of banana peels potentials as electrode material supercapacitor  EDLC type. Keyword: activated carbon; porosity; specific capacitance; and supercapacitor electrode.
Co-Authors Ahmad Nasir Pulungan Aulia, Amanda Ayu Andini ayumi, Sheilla Maliza Azzahra, Vina Octavia Br Manik, Trivena Myta Br Nadeak, Stephani Bintang N. Br Napitupuli, Monika Shinta Kasih Br Sebanyang, Resi Mai Linda Etaminta Br Sipahutar, Desy Meriani Cahayo, Maf'ud Damanik, Angelica Damanik, Wicha Rosari Dikki Miswanda Eddiyanto Eddiyanto Fahmi, Jam'an Fahmi, Jaman Fahmi, Jam’an Faradilla, Putri Fitriani, Novi Artika Husna, Wiki Nadia Irma Syahputri Jasmidi Khairahma Khairahmi Limbong, Julian Lubis, Ghania Dhia Ulhaq Lumbantoruan, Sifra H.R Manalu, Anrian Haholongan Manullang, Okto Panca Manullang, Riska Greselia Masruroh MASRUROH Mendrofa, Bulan Susanti Moondra Zubir Nainggolan, Lidya Revalina Nasution, Dhea Ananda Novrizaldi Wardana Nurdin Siregar Puandra, Esti Miska Pulungan, Ahmad Shafwan purba, Gracia Purba, Sunita Karin Putri Ayunicha Putri Faradilla Rahmadyani, Zaskia Rahmah, Alfiatur Rini Selly, Rini S, Abd Hakim Safitri, Wulan Dwi Sagala, Novitri Yolanda Sembiring, Rinawati Shallomita, Grace Sigalingging, Olivia Gina Ananta Sihotang, Pelita Silalahi, Sarina Septiani Silvianti, Risna Simamora, Astuty Evalina Simamora, Elisabeth Siregar, Ida Cathy Everyanti Siregar, Koriatul Jannah Siregar, Nuraini Tambunan, Ida Mariati Wardana, Dian Warsito Warsito Warsito Zainollah, Ahmad Zubir, Moondra