Herdini Herdini
Jurusan Pendidikan MIPA, FKIP, Universitas Riau, Pekanbaru

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Studi Inhibisi Korosi Karboksimetil Kitosanpada Permukaan Baja Lunakdalam H2SO4

VALENSI Vol 4, No 1 (2014): Jurnal Kimia Valensi Volume 4//No.1//Mei 2014
Publisher : Program Studi Kimia, Fakultas Sains dan Teknologi, UIN Syarif Hidayatullah Jakarta

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Abstract

Abstrak Telah dipelajari efisiensi dan mekanisme inhibisi korosi karboksimetil kitosan (KMK) pada permukaan baja lunak dalam larutanH2SO4.Efisiensi inhibisi korosi ditentukan dengan menggunakan metode pengukuran berat hilang (Weight Loss Method), sedangkan mekanisme inhibisi korosi dipelajari berdasarkan hasil analisis karakterisasi Scanning Electron Microscope- Energy Dispersive X-ray(SEM-EDX). Hasil penelitian menunjukkan bahwa efisiensi inhibisi korosi KMK dalam H2SO4 mencapai 65.12%. Hasil analisis karakterisasi memperlihatkan mekanisme inhibisi KMK pada permukaan baja lunak melalui peristiwa adsorpsi kimia membentuk lapisan pasif berupa senyawa Fe-khelatmelalui unsur O dari gugus –OH dan N dari gugus –NH2 dari molekul KMK Kata kunci : Efisiensi inhibisi korosi, karboksimetil kitosan, mekanisme inhibisi   Abstract The corrosion inhibition efficiencyandmechanism ofcarboxymethylchitosan(CMC) on the surface ofmild steel in H2SO4 solution has studied. Determination of the corrosion inhibition efficiency measurement used Weight Loss Method (WLM), whereas the mechanism of corrosion inhibition studied based on the analysis characterizing Scanning Electron Microscope-Energy Dispersive X-ray (SEM-EDX). The results showed that the corrosion inhibition efficiency of CMC reaches 65.12%. Characterization analysis results showed inhibition mechanism CMC on mild steel surface through chemical adsorption events form a passive layer of Fe-chelate compounds through O elementof -OH group and N element of -NH2 group of molecules KMK. Keywords : corrosion inhibittion efficiency, carboxymethyl chitosan, inhibition mechanism

PENERAPAN STRATEGI PEMBELAJARAN AKTIF PRACTICE-REHEARSAL PAIRS UNTUK MENINGKATKAN PRESTASI BELAJAR SISWA PADA POKOK BAHASAN KOLOID DI KELAS XI IPA SMA NEGERI 2 PEKANBARU

Jurnal Online Mahasiswa (JOM) Bidang Keguruan dan Ilmu Pendidikan Vol 3, No 1 (2016): Wisuda Februari 2016
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Keguruan dan Ilmu Pendidikan

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Abstract : Research on the application of active strategies Practice-Rehearsal Pairs have been conducted to determine whether application of active strategies Practice-Rehearsal Pairs can improve student achievement on the Colloid subject in class XI SMAN 2 Pekanbaru. The research’s form is an experimental research with pretest-posttest design. The research was conducted on the even semester in academic year 2014/2015. The sample consisted of two classes, class XI Science 1 as the experimental and class XI Science 2 as the control class which randomly selected after tests of normality and homogeneity. Experimental class was treated by given a strategies Practice-Rehearsal Pairs, while the control class was not given strategies Practice-Rehearsal Pairs. Data collection technique use this the test. Data analysis technique use this the-test. Based on the results of the final data processing obtained tcount> ttable, it is 2,560 > 1,669. This shows that the application of active strategies Practice-Rehearsal Pairs can improve student achievement on the Colloid subject in class XI Science SMAN 2 Pekanbaru, the effect of an increase of 9,49%.Keywords: Colloid, Active Strategies, Learning Achievement, Practice-Rehearsal Pairs.

PENERAPAN STRATEGI PEMBELAJARAN AKTIF FORMASI REGU TEMBAK UNTUK MENINGKATKAN PRESTASI BELAJAR SISWA PADA POKOK BAHASAN KESETIMBANGAN KIMIA DI KELAS XI IPA SMA NEGERI 10 PEKANBARU

Jurnal Online Mahasiswa (JOM) Bidang Keguruan dan Ilmu Pendidikan Vol 3, No 1 (2016): Wisuda Februari 2016
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Keguruan dan Ilmu Pendidikan

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Abstract : This research is about the application of active learning the firing line strategy that has conducted to know the increasing of student’s learning achievement on chemical equilibrium topic in class XI IPA in 10 Senior High School Pekanbaru. This research was experiment by design pretest and posttest. The sample determined randomly after doing normality and homogeneity test of 5 classes as population and then class XI IPA 5 as experiment class and XI IPA 4 as class group. The experiment group was applied by the application of active learning the firing line strategy. The data analysis technique used was t - test. Based on the tabulation of last data obtained tcount>ttable was 2,36 ≥ 1,67 meant that the application of active learning the firing line strategy could increase the student’s learning achievement on Solubility and Constanta Solubility Product topic in class XI IPA in 10 Senior High School Pekanbaru. Category increase the student’s learning achievement trhough active learning the firing line strategy on the subject of chemical equilibrium is a high category of 0,77.Keywords: The Firing Line, Active Learning, Achievement, Chemical Equilibirium

POTENSI TUMBUHAN AKAR TAPAK KUDA (BAUHINIA HULLETTII PRAIN) SEBAGAI SUMBER SENYAWA ANTIOKSIDAN

CHEMPUBLISH JOURNAL Vol 1, No 1 (2015)
Publisher : Program Studi Kimia FST Universitas Jambi

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Abstract

Akar tapak kuda (Bauhinia hullettii Prain) merupakan tumbuhan  dari genus Bauhinia yang banyak dijumpai di Indonesia. Tumbuhan Bauhinia dilaporkan kaya akan senyawa flavonoid dan stilbenoid. Dua senyawa flavanon (1 dan 2) dan senyawa fenolik (3) terdapat pada kulit batang dan daun akar tapak kuda.Uji aktivitas antioksidan dari tiga senyawa terhadap radikal DPPH menunjukkan aktifitas antioksidan yang sangat kuat untuk senyawa 1 (5,7,3’,5’-tetrahidroksi flavanon)  dan  3 (asam 3,4,5-trihidroksibenzoat).  Senyawa 2 (5,7,4’-trihidroksi-6-metilflavanon) tidak aktif sebagai antioksidan dengan IC50>1000 µg/mL. Senyawa 1 dan 3 diketahui lebih aktif daripada Vitamin C dengan IC50 masing-masing 6,33 dan 1,26 µg/mL. Kata Kunci: Bauhinia hullettiiPrain, flavonoid, fenolik, aktivitas antioksidan

PENERAPAN STRATEGI PEMBELAJARAN AKTIF GROUP TO GROUP EXCHANGE (GGE) UNTUK MENINGKATKAN HASIL BELAJAR SISWA PADA POKOK BAHASAN KESETIMBANGAN KIMIA DI KELAS XI IPA SMA NEGERI 11 PEKANBARU

Jurnal Online Mahasiswa (JOM) Bidang Keguruan dan Ilmu Pendidikan Vol 5: Edisi 2 Juli-Desember 2018
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Keguruan dan Ilmu Pendidikan

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Abstract

Abstract: Research on active learning strategy group to group exchange (GGE) has been implemented in SMAN 11 Pekanbaru. The research aimed to know the increase student’s achievement learning and the influence of GGE strategy on students achievement learning on the subject of Chemical Equilibrium in XI IPA SMAN 1 Pekanbaru. The type of research is experimental research with pretest-posttest design . XI IPA SMAN 11 Pekanbaru consisting of 3 classes performed normality and homgeneity test using prerequisite data so that obtained 2 randomly selected samples that is student in class XI IPA 2 as an experimental class and students in class XI IPA 3 as a control class. The experimental class is the class that applied GGE active learning strategy while the control class is not applied GGE active learning strategy.This research instrument is a quastion of chemical equilibrium that has been tested validation and reliability and obtained valid and reliable data as research instrument. The hypothesis testing using U Mann-Whitney test obtained z arithmetic > z table is 3.89> 1, 64, based on hypothesis testing concluded that the implementation of GGE active learning strategy can increase student achievement learning on the subject of chemical equilibrium in class XI IPA SMAN 11 Pekanbaru . The influence of GGE's active learning strategy on student achievement learning is 34.3%.Keywords : Chemical Equilibrium,Students Achievement, Group to Group Exchange (GGE)

POTENSI TUMBUHAN AKAR TAPAK KUDA (BAUHINIA HULLETTII PRAIN) SEBAGAI SUMBER SENYAWA ANTIOKSIDAN

CHEMPUBLISH JOURNAL Vol 1 No 1 (2016): Chempublish Journal
Publisher : Universitas Jambi

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Abstract

Akar tapak kuda (Bauhinia hullettii Prain) merupakan tumbuhan  dari genus Bauhinia yang banyak dijumpai di Indonesia. Tumbuhan Bauhinia dilaporkan kaya akan senyawa flavonoid dan stilbenoid. Dua senyawa flavanon (1 dan 2) dan senyawa fenolik (3) terdapat pada kulit batang dan daun akar tapak kuda.Uji aktivitas antioksidan dari tiga senyawa terhadap radikal DPPH menunjukkan aktifitas antioksidan yang sangat kuat untuk senyawa 1 (5,7,3’,5’-tetrahidroksi flavanon)  dan  3 (asam 3,4,5-trihidroksibenzoat).  Senyawa 2 (5,7,4’-trihidroksi-6-metilflavanon) tidak aktif sebagai antioksidan dengan IC50>1000 µg/mL. Senyawa 1 dan 3 diketahui lebih aktif daripada Vitamin C dengan IC50 masing-masing 6,33 dan 1,26 µg/mL. Kata Kunci: Bauhinia hullettiiPrain, flavonoid, fenolik, aktivitas antioksidan

PENERAPAN MODEL PEMBELAJARAN PROBLEM POSING UNTUK MENINGKATKAN PRESTASI BELAJAR PESERTA DIDIK PADA POKOK BAHASAN KESETIMBANGAN KELARUTAN DI KELAS XI MIA SMAN 6 PEKANBARU

Jurnal Online Mahasiswa (JOM) Bidang Keguruan dan Ilmu Pendidikan Vol 5: Edisi 2 Juli-Desember 2018
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Keguruan dan Ilmu Pendidikan

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Abstract: The purposes of research are to know the improvement of student learning achievement and the category by implementing problem posing learning model to increased student achievment on the subject of solubility equilibrium in class XI MIA SMAN 6 Pekanbaru.. This research is experimental research using Design Randomized Control Group Pretest-Posttest. The population in the research consist of 4 class, that is XI MIA 1, XI MIA 2, XI MIA 3 and XI MIA 4. The research sample consisted two class, class XI MIA 1 as experiment class and class XI MIA 2 as control class that has tested by normality test using Liliefors test and homogeneity test using equality of two average test. Hypothesis was done by using test-t right side and N-gain test to choiced the improvement category of student achievement. Research result shown that the implementation of problem posing learning model can improve student learning achievement on the solubility equilibrium subject where tarithmetic = 2,53 > ttable = 1,67 and category increase students achievement in the experimental class at 0,79 with high categories.Keywords : Learning Model Problem Posing, Learning Achievement, Solubility Equilibrium

Development of interactive multimedia based on Lectora Inspire in chemistry subject in junior high school or madrasah tsanawiyah

JOURNAL OF EDUCATIONAL SCIENCES Vol 2, No 1: January 2018
Publisher : Universitas Riau

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Abstract

The research aims to develop interactive multimedia based Lectora Inspire on science chemistry subjects for SMP/MTs. The research method using the design of research and development (Research and Development) with a model Plomp, which consists of four phases; initial investigation, design, realization and construction, and validation, test and revision. The research was conducted at the University of Riau FKIP. The object of research is interactive multimedia Lectora Inspire. Data collected by validating based interactive multimedia Lectora Inspire to 3 validator (media expert and subject matter experts) and limited trial by users that teachers and students in SMP 4 and SMP Babussalam Pekanbaru. The results showed an average score of validator 98.20% . Score of limited trial based on questionnaire responses of teachers and students each obtained an average score of 98.78% and 97.03%. From the result of the average score of the validation and limited trial of interactive multimedia based Lectora Inspire for chemistry subjects for SMP / MTs valid and can be used as a learning media.

Interactive multimedia based on autoplay media studio 8 for chemistry on rate of reaction topics for class Xi SMA/Ma

JURNAL PENDIDIKAN KIMIA (JPKim) Vol 9, No 3 (2017): Desember 2017
Publisher : JURNAL PENDIDIKAN KIMIA (JPKim)

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Abstract

A valid and practical learning Interactive Multimedia of Autoplay Media Studio 8 for Rate of Reaction topics has been developed. The research method was Research and Development with Plomp model which consist of 4 steps; Prelimenary Investigation, Design, Realization, and Validation, evaluation, revision. Media was validated by three validators and limited trial by practitioners (users). The results showed an average score of validation was 96.12%. Based on questionnaire responses of 3 teachers and 20 students each earned an average score of 96.25% and 94.5%, respectively. From the results of the average validation score and limited trial score of Autoplay media studio 8 Interactive Multimedia for Rate of Reaction topics was valid and can be used as a learning media.Key words: autoplay media studio 8, interactive multimedia, rate of reaction

ISOLASI DAN KARAKTERISASI SENYAWA METABOLIT SEKUNDER FRAKSI ETIL ASETAT DARI KULIT BATANG TUMBUHAN ¬Bauhinia purpurea L

JURNAL PENDIDIKAN KIMIA (JPKim) Vol 7, No 1 (2015): April 2015
Publisher : JURNAL PENDIDIKAN KIMIA (JPKim)

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Abstract Isolation and characterization secondary metabolite of ethyl acetate fraction from Bauhinia purpurea L stem bark has been conducted. Bauhinia purpurea L belonging to biggest family of flowering plant in Asia. This plant was choosed as study sample evidence remedy effect for some disease like ulcer, cough, tumor, puffing, and snakebite. Isolation conducted by extraction and chromatograph method. Extraction by maceration technique used non polar and semipolar solvent alternally, n-hexane, dichloromethane, and ethyl acetate. The extract separated by liquid vacuum, coloum, and flash chromatograph until obtained pure compound. The melting point of compound was determined by John-Fisher apparatus.The compound structure was determined by UV-Vis, IR, 13C-NMR spectroscopic.The compound spectroscopy data was compared with standard compound data.Extraction resulted n-hexane fraction, dichloromethane fraction, and ethyl acetate fraction. Separation of ethyl acetate fraction resulted white crystalline powder and has melting point 220-2210C. Evidence on spectroscopy data were estimated the compound was a stigmasterol glycoside.Key word : Bauhinia purpurea L; stem bark; ethyl acetate; stigmasterol glycoside