Santa, Eldat Wira
Manado State University

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Sintesis ferrat dari Fe(NO3)3 dan NaOCl sebagai pendegradasi zat pewarna makanan tartrazine Eldat Wira Santa; La Baru Moses
Jurnal Kimia Fullerene Vol 3 No 1 (2018): Fullerene Journal of Chemistry
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (475.17 KB) | DOI: 10.37033/fjc.v3i1.31

Abstract

This investigation was carried out in order to synthesize ferrate (FeO42-) and was applied to the degradation of the food coloring agent of tartrazine. The synthesis of ferrate is carried out by the reaction of Fe(NO3)3 and NaOCl as oxidants in alkaline conditions. The synthesis was monitored using a UV-Vis spectrophotometer and resulted in a wavelength of 510 nm. The resulting ferrate is crystallized using KCl. The resulting crystals are potassium ferrate of 0.977 g. The angle of potassium ferrate 2q is measured with X-ray diffraction (XRD), which produces an angle of 2q of 28,480. Potassium ferrate was applied to degrade the tartrazine dye that was controlled using the UV-Vis spectrophotometer. The effect of several parameters on the tartrazine dye that degrades the reaction, such as the pH and the molar ratio of ferrate and tartrazine, was also studied in this study. The results showed that ferrate can degrade tartrazine at pH 9.6 with the highest degradation present in the molar ratio of ferrate and tartrazine 1: 5 which is 98.45%. This suggests that ferrate are an alternative and environmentally friendly substance that can be used to degrade tartrazine dye.
Investigating Learners' Conceptual Progression on pH of Solution, Acid-Base Titration, and Buffer Solutions Santa, Eldat Wira; Sumari, Sumari; Nur, Hadi; Setiawan, Nur Candra Eka; Muntholib, Muntholib
Tadris: Jurnal Keguruan dan Ilmu Tarbiyah Vol 9 No 2 (2024): Tadris: Jurnal Keguruan dan Ilmu Tarbiyah
Publisher : Universitas Islam Negeri Raden Intan Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24042/tadris.v9i2.23169

Abstract

This study aims to explore the development of understanding of the concepts of pH, acid-base titration, and buffer solutions among 11th-grade students and 2nd- and 4th-semester university students in chemistry education. It employs a cross-sectional design using open-ended questions and interview guidelines to collect data from 153 11th-grade students, 30 second-semester university students, and 40 fourth-semester university students. The open-ended questionnaire consists of 9 items (2 questions on the pH of solutions, 4 questions on acid-base indicators and titration, and 3 questions on buffer solutions and salt hydrolysis) on a continuous scale, with an Aiken's kappa validity of 0.61 (substantial agreement) and a Cronbach's Alpha reliability (KR-20) of 0.75 (acceptable). The results indicate that scientific understanding of pH concepts, such as the pH of solutions, acid-base titration, and buffer solutions, improves with education. However, comprehension of complex concepts remains low. The study's implications highlight the need for curriculum development and the selection and implementation of learning strategies that enable students to learn in a structured, gradual, and coherent manner. Curriculum development should map out subject matter, distinguish essential from non-essential content, and organize material from simple and essential topics to more complex and non-essential ones.