Dahlia Rosma Indah
Universitas Pendidikan Mandalika Mataram

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Pengembangan Buku Ajar Dengan Model Inkuiri Berbasis Strategi Konflik Kognitif Untuk Meningkatkan Keterampilan Berpikir Kritis Siswa Dahlia Rosma Indah; Husnul Hatimah
Hydrogen: Jurnal Kependidikan Kimia Vol 8, No 2 (2020): Hydrogen: Jurnal Kependidikan Kimia
Publisher : Universitas Pendidikan Mandalika Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (690.464 KB) | DOI: 10.33394/hjkk.v8i2.3156

Abstract

Chemical bonding contains basic concepts that are used to understand almost any topic in chemistry. Several research results show that there are still many misconceptions. Therefore, teaching materials are needed that can provide a correct understanding of the basic concepts in chemical bonding materials. This study aims to produce inquiry model chemistry teaching materials with cognitive conflict strategies for Muallimat NW Pancor high school. The development method used definne, design, development and dissemination. Data analysis was conducted in the form of product validity tests and students' critical thinking skills tests. However, in this development research, it only stopped at the third stage. The data obtained were quantitative and qualitative. The results  is (1) the feasibility of the material was 84% (very feasible); (2) the systematic feasibility of the presentation is 85% (very feasible); (3) language feasibility is 85.33% (very feasible). So that overall the teaching materials produced are categorized as very feasible and can be used in chemistry learning.
Karakterisasi Karbon Baggase Teraktivasi dan Aplikasinya untuk Adsorpsi Logam Tembaga Dahlia Rosma Indah; Safnowandi Safnowandi
Hydrogen: Jurnal Kependidikan Kimia Vol 7, No 2 (2019): Hydrogen: Jurnal Kependidikan Kimia
Publisher : Universitas Pendidikan Mandalika

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (779.427 KB) | DOI: 10.33394/hjkk.v7i2.1912

Abstract

Bagasse is waste produced from the process of milking or extracting sugarcane stems. Baggase can be optimized in terms of use value and its function as an alternative technology, namely as an active carbon manufacturing material that can be used as a copper (Cu) adsorbent. This study discusses the functional baggase activated carbon group of phosphoric acid and nitric acid using Fourier Transform Infra Red (FTIR) and its application as a copper metal adsorbent in silver craft waste in Ungga Village, Praya, Central Lombok. The production of activated bagasse carbon consists of three stages, namely first dehydration by burning bagasse until it turns into carbon, the second carbonation is heating at 500ºC, carbon results are 100-200 mesh and third, activation by soaking 50 grams of carbon in 500 mL of 20% phosphoric acid and 20% nitric acid for 12 hours. After that the carbon is dried at 110ºC and finally heated at 500ºC for 1 hour. The bagasse carbon that has been made is put into 25 mL of waste water sample with a mass of 2 grams of adsorbent. Samples were then stirred at 30, 60, 90, 120 and 150 minutes contact time variations at a speed of 180 rpm using a batch system. The optimum contact time that is used to calculate the efficiency of copper metal content reduction is by calculating the difference in the metal content of copper metal before it is adsorbed and after it is adsorbed using activated carbon baggase. Concentrations of all copper metals were analyzed using Atomic Absorption Spectrophotometer (AAS). Identification using FTIR spectrophotometer shows that carbon baggase in this study contains functional groups C = O, C = C, C-C, N = O, C = N, C-OH, CH2 and C-H. From the research it was found that the copper metal content in the sample was 14.5710 ppm. The optimum contact time on copper metal adsorption is at 120 minutes contact time which results in optimum adsorption efficiency on copper metal that is 84.88%. Activated carbon baggase is an effective adsorbent to reduce levels of copper metal in silver craft waste.