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Analisis Residu Pestisida dalam Tomat, Cabai Rawit dan Wortel dari Beberapa Pasar Tradisional di Sulawesi Utara Abdon Saiya; Dokri Gumolung; Joice Dorsila Susana Caroles
Jurnal Kimia Fullerene Vol 3 No 2 (2018): Fullerene Journal of Chemistry
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

One method to eradicate plant pests carried out by farmers in the North Sulawesi area is to use pesticides because they are considered easy to obtain, the price is still affordable, and very effective at killing plant pests. However, improper use of pesticides results in the loss of pesticide residues in plants which causes environmental pollution, health problems in humans and inhibits trade. Therefore, it is necessary to monitor the use of pesticides through the fulfillment of the maximum residual limit (BMR). This study aims to analyze pesticide residues in tomatoes, cayenne pepper, and carrots using the method of High Performance Liquid Chromatography (HPLC) which was previously optimized and validated. The research samples were tomatoes, cayenne pepper, and carrots, taken from Pasar Bersehati Tomohon, Pasar Karombasan Manado, and Pasar Kawangkoan Minahasa, then taken to the Chemistry Laboratory of Manado State University to be extracted and analyzed. The results of this study indicate that pesticides with chlorpyrifos active ingredients were detected in almost all samples analyzed, although the levels were still below the specified BMR value, ie 1 mg/kg sample. The highest chlorpyrifos level was found in tomato samples taken from Pasar Kawangkoan Minahasa, which was 0.3150 mg/kg. The results of this study also showed that samples that were washed before extraction caused a decrease in the residual content of the petisides.

Penurunan konsentrasi logam kromium dengan fotokatalis titanium dioksida (TiO2), dan absorben SiO2-CFA Joice Dorsila Susana Caroles
Jurnal Kimia Fullerene Vol 3 No 1 (2018): Fullerene Journal of Chemistry
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Decrease in the concentration of chromium metal by photocatalysis process, and adsorption has been done on river water samples. Photocatalysis using TiO2 photocatalyst, while adsorption using SiO2 CFA adsorbent was done with the aim of obtaining a picture of the effectiveness between the use of photocatalysis process and the adsorption process to reduce the concentration of chromium metal. The decrease of chromium metal concentration after photocatalysis, and adsorption for 6 hours was analyzed by AAS. Result of analysis showed decrease of chromium metal concentration through bigger photocatalysis that is 79,30% compared through adsorption only equal to 39,4%.

Imobilisasi silika ke dalam TiO2 untuk fotokatalis Joice Caroles
Jurnal Kimia Fullerene Vol 2 No 2 (2017): Fullerene Journal of Chemistry
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Modification of TiO2 photocatalyst with SiO2 absorbent has been performed. Modification is done by immobilizing SiO2 into TiO2. Photocatalyst of TiO2-SiO2 result from immobilization, then analyzed using SEM-EDS instrument. The analysis was performed to see the immobilized silica. The results of the analysis showed that the silica content of 47.90% immobilized on TiO2 photocatalyst.

Optimasi Spesiasi Kromium Ke Bentuk Cr(III) - Tanat Jenifer Alfonda Walewangko; Djefry Tani; Joice Caroles
Jurnal Kimia Fullerene Vol 5 No 1 (2020): Fullerene Journal of Chemistry
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

This research was conducted to determine the heavy metal species of Cr (III). Determination of heavy metals is determined based on the required chromium species using the UV-Vis spectrophotometry method. The sample used was CrCl3.H2O and the complexing agent was tannic acid. This research was conducted to determine the effect of pH, concentration and time of stability by finding the optimum conditions of the chromium - tanic acid complex. The optimum pH is at pH 11, the optimum concentration is at a ratio of 5: 1 concentration (Cr: tanic acid), the stability of time is at the 10th minute.

Ekstraksi silika yang terkandung dalam limbah abu terbang batu bara Joice Dorsila Susana Caroles
Jurnal Kimia Fullerene Vol 4 No 1 (2019): Fullerene Journal of Chemistry
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Coal fly ash waste contains metal oxides, one of which is silica. The presence of silica in coal fly ash allows the waste to be used directly as an adsorbent. The use of silica contained in coal fly ash can be carried out maximally by silica purification. Silica purification by extracting silica from coal fly ash aims to minimize unnecessary metal oxide levels (impurities). Analysis of silica content carried out before and after the extraction process aims to determine the levels of silica compared to other metal oxides. The procedure is done, namely sieving to separate samples from impurity material, then analyzing using SEM-EDS instruments, and then proceed with the silica extraction process. The results of the analysis showed a greater percentage of silica (SiO2) content of 67.68% compared to Al2O3 of 16.80%; while the extracted silica content was 80.42%.

Penerapan Model Pembelajaran Problem Based Learning (Pbl) Pada Materi Asam Basa Siswa Kelas Xi Ipa Di Sma Negeri 1 Tenga Oktaviani Rampi; Emma Pongoh; Joice Caroles
Oxygenius Journal Of Chemistry Education Vol 3 No 2 (2021): Oxygenius: Journal of Chemistry Education
Publisher : Chemistry Department, Universitas Negeri Manado

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37033/ojce.v3i2.304

This research aims to determine the application of problem based learning (PBL) learning models on acid-base material for class XI science at SMA Negeri 1 Tenga. This research was conducted in class XI SMA Negeri 1 Tenga with a sample of 25 people. The research design used was the post-test-only control group design experimental method. The experimental class uses a problem based learning (PBL) model and the control class uses conventional learning. Analysis of hypothesis testing using t-test with a significant level of = 0.05 and success (dk) = 48. The test results obtained show that the results of tcount > ttable or 3.62 > 2.010, thus H0 is rejected and Ha is accepted, and the average the average student learning outcomes of the experimental class were 81.92, which was greater than the learning outcomes of the control class was 72.96. This shows that there is a significant difference between the average score (post-test) of the experimental group and the control group. So it can be concluded that there is a difference in the average learning outcomes of students who use the problem based learning (PBL) learning model with the learning outcomes of students who use conventional learning on acid-base materials.

Penggunaan Three-Tier Diagnostic Test Untuk Pemetaan Tingkat Penguasaan Elektrokimia Mahasiswa Kimia Semester II Elvian Anggelina Soru; Hardin Foster Rares; Joice Caroles
Oxygenius Journal Of Chemistry Education Vol 2 No 1 (2020): Oxygenius : Journal of Chemistry Education
Publisher : Chemistry Department, Universitas Negeri Manado

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37033/ojce.v2i1.132

The purpose of this study was to determine the level of understanding of concept maps of semester II chemistry students using a three-tier diagnostic test on electrochemical subjects with multimedia-based learning. The research was carried out in the Department of Chemistry, FMIPA, UNIMA in the even semester of the 2018/2019 school year. The research method used is One-shot Case, with a sample of the research that is a class of chemistry classes for a certain year as many as 12 people. Multimedia instruments are made by utilizing animation and video from the internet which is packaged in Ms. Power point, and the electrochemical three-tier diagnostic test instrument is made according to the subject being taught. Then the test instrument was validated and 15 questions were produced. It was found the map data on the level of understanding of electrochemical concepts namely the average number of students who understood the concept by 41.6%, the average number of students experiencing misconceptions both misconceptions (+), misconceptions (-) and misconceptions by 30.033%, average number students do not understand the concept as much as 11.1%, there are 8.3% students who are not sure of the concept they have, and 8.3% there are students who do not understand the concept of electrochemistry. Thus, it was concluded that a three-tier electrochemical diagnostic test was able to reveal a map of students' level of understanding of the chosen topic

Korelasi Model Pembelajaran Student Team Achievement Division (STAD) Terhadap Hasil Belajar Siswa Pada Materi Konsep Asam Basa Fladi Rivera Kalubota; Dokri Gumolung; Joice D. S. Caroles
Oxygenius Journal Of Chemistry Education Vol 3 No 1 (2021): Oxygenius: Journal of Chemistry Education
Publisher : Chemistry Department, Universitas Negeri Manado

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37033/ojce.v3i1.267

This study aims to determine how much the correlation value in the use of the learning model Studen Team Achievement Division (STAD) on student learning outcomes. The steps of the STAD learning model, namely: 1) convey learning objectives and motivate students, 2) organize students into study group consisting of 4-6 people, 3) convey information, 4) guide groups to work and study, 5) elevate students learning outcomes, 6) to give appreciation. This research wash conducted at SMA Negeri 5 Halmahera Utara in the even semester of the 2019-2020 school year. The sample used was 20 students of class XI-MIPA 1. Data collection technique using students attitude questionnaires and posttest questions. The results of the study a correlation coefficient value of 0.731, the value of the determinant coefficient of 53.44%. Score tcount > ttable (4.537 > 1.73406) so that there is a significant influence between the STAD learning model and student learning outcomes on the acid-base concept material.

Studi Kelayakan Penuntun Praktikum Asam Basa Berbasis Bahan Lingkungan Menggunakan Model 3-D Dan Penerapan Metode Inkuiri Terbimbing Untuk Meningkatkan Hasil Belajar Siswa SMA Negeri 1 Tenga gerry lumolos; Dokri Gumolung; Joice Caroles
Oxygenius Journal Of Chemistry Education Vol 1 No 2 (2019): Oxygenius : Journal of Chemistry Education
Publisher : Chemistry Department, Universitas Negeri Manado

Practicum guides are printed teaching materials that students can use in the learning process. This development research aims to determine the feasibility of an acid base-based practicum guide for environmental materials with a 3-D model and to improve student learning outcomes through practicum activities and the application of guided inquiry methods. The subject of this research was class XI IPA 1 at SMA Negeri 1 Tenga. The feasibility test for large groups has an average percentage of 88.24% which means that this practical guide is suitable for use with valid qualifications. Student learning outcomes using post test scores with the technique of statistical analysis of one sample t-test (one sample t-test). The results of the one-sample t-test hypothesis at a level of α = 5% were obtained tcount = 4.604> ttable = 1.708. The results of this study indicate that the guidelines for acid-base-based practicum for environmental materials are appropriate to be used in chemistry learning, and the use of acid-based practicum guides for environmental materials with the application of guided inquiry methods can improve student learning outcomes in acid-base material

Pengaruh Penerapan Strategi Pembelajaran REACT (Relating, Experiencing, Applying, Cooperating, dan Transferring) Terhadap Hasil Belajar Siswa Pada Materi Konsep Asam Basa Alfath Fitrilia Taraufu; Dokri Gumolung; Joice Caroles
Oxygenius Journal Of Chemistry Education Vol 2 No 2 (2020): Oxygenius : Journal of Chemistry Education
Publisher : Chemistry Department, Universitas Negeri Manado

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37033/ojce.v2i2.177

Penelitian ini bertujuan untuk mengetahui besarnya pengaruh penerapan strategi pembelajaran REACT terhadap hasil belajar siswa pada materi konsep asam basa menggunakan konteks kimia. Penelitian ini dilaksanakan di SMA Negeri 1 Tondano pada tahun ajaran 2019/2020 di kelas XI IPA 1 dengan jumlah siswa sebanyak 23 orang. Materi konsep asam basa yang diajarkan di kelas XI IPA 1 dikaitkan dengan kehidupan sehari-hari. Hasil pengolahan data hubungan antara nilai angket dan posttest menunjukan respon positif dalam pembelajaran menggunakan strategi pembelajaran REACT. Data hasil penelitian berupa angket dan posttest dianalisis melalui uji hipotesis yaitu uji regresi sederhana dan uji korelasi product moment. Uji regresi sederhana menunjukan bahwa semakin tinggi sikap siswa terhadap strategi pembelajaran REACT (X) maka semakin tinggi hasil belajar siswa (Y), hal ini menunjukan adanya pengaruh variabel X (sikap) dan variabel Y (hasil belajar). Hasil uji korelasi product moment diperoleh nilai rxy yaitu 0,6466 yang menunjukan tingkat hubungan yang kuat. Hasil koefisien penentu untuk mengetahui pengaruh pembelajaran REACT terhadap hasil belajar diperoleh sebesar 41,82%. Dari hasil yang diperoleh dapat dilihat bahwa terdapat pengaruh penerapan strategi pembelajaran REACT terhadap hasil belajar siswa pada materi konsep asam basa menggunakan konteks kimia.

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