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Alotrop
Published by Universitas Bengkulu
ISSN : -     EISSN : -     DOI : -
Core Subject : Science,
Chemistry
Jurnal Alotrop adalah majalah ilmiah resmi yang diterbitkan oleh Program Studi Pendidikan Kimia Jurusan Pendidikan MIPA Fakultas Keguruan dan Ilmu Pendidikan Universitas Bengkulu, sebagai sumbangannya kepada pengembangan Ilmu Kimia dan Pendidikan Kimia yang diterbitkan dalam Bahasa Indonesia yang memuat hasil-hasil penelitian, telaah/tinjauan pustaka, kasus lapangan atau gagasan dalam bidang ilmu Kimia dan Pendidikan Kimia
Arjuna Subject : -
Articles 87 Documents
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ANALISIS KAPASITAS ADSORPSI SILIKA DARI PASIR PANTAI PANJANG BENGKULU TERHADAP PEWARNA RHODAMINE B Madina, Fitri Esa; Elvia, Rina; Candra, I Nyoman
Alotrop Vol 1, No 2 (2017)
Publisher : FKIP University of Bengkulu

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Abstract

[ANALYSIS OF SILICA ADSORPTION CAPACITY FROM THE SAND OF PANTAI PANJANG BENGKULU  AGAINST RHODAMINE B DYES ] This research was aimed to study the adsorption capacity of synthetic silica on Rhodamine B dyes. Synthetic silica was obtained from the sand of Pantai Panjang  Bengkulu by alkali fusion method using KOH at  360 °C for 4 hours in furnace to obtain potassium silicate crystals (K2SiO3). The crystals were then added 500 mL aqua DM, stirred and sterilized for 24 hours folloed by filtered. The filtrate was dropped with 10 M HCl solution until the pH of filtrate solution reached at 1 to 2 and formed a silent white gel for 24 hours. Moreover,  the gel was filtered with filter paper and washed with aqua DM until pH is neutral and free from KCl, and dried in an oven at 60 °C for 18 hours. The obtained silica powder is then smoothed with mortar and weighed. The adsorbent of Rhodamine B dyes using the synthetic silica powder was performed on pH  variation at 2, 3, 4, 5, 6, and 7 , and  variation of contact time at 10, 20, 30, 40, 50, and 60 min. The results showed that the optimum  condition of adsorption of Rhodamine B by silica from Pantai Panjang sand occured at optimum pH   2 and optimum contact time  20 minutes; with adsorption capacity of 4.95 mg / g and 4.79 mg/g; and with adsorption efficiency of 99.00% and 95.89%.
PERBANDINGAN MODEL PEMBELAJARAN KOOPERATIF TIPE THINK TALK WRITE (TTW) DAN CREATIVE PROBLEM SOLVING (CPS) TERHADAP MINAT DAN HASIL BELAJAR KIMIA SISWA Pratiwi, Ghea Sefriza; Bahar, Amrul; Elvia, Rina
Alotrop Vol 3, No 2 (2019)
Publisher : FKIP University of Bengkulu

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Abstract

The purpose of this study is to describe the comparison of Think Talk Write learning models and Creative Problem Solving learning models to the interests and learning outcomes of chemistry in basic chemical law material. This research was conducted in January-May 2019. The research conducted was a kind of quasi-experimental research. The population of this study was class X MIA, totaling 136 students in SMAN 8 Kota Bengkulu in the academic year 2018/2019. Sampling was carried out after the normality and homogeneity test, so the X MIA 2 class was selected using Think Talk Write and X MIA 3 models that used the Creative Problem Solving model with a total of 68. Analysis of the data used was mean, normality test, test homogeneity, interest questionnaire analysis, N-Gain Score test and hypothesis test (t test). In general, both of these learning models are able to increase students 'interest and learning outcomes of chemistry, where the percentage of students' interest in learning chemistry in the Think Talk Write model is 80.5% and categorized as good, for the class of Creative Problem Solving model the percentage is 76.6% and also categorized as good. For the value of N-Gain score on Think Talk Write (TTW) class is and categorized as high while in the Creative Problem Solving class is 0.62 and is categorized as medium. The t-test results on the affective aspects are sig. (2-tailed) of 0.015 and on the cognitive aspect of 0.001. It states that there are significant differences in the interest and learning outcomes of chemistry that apply the Think Talk Write (TTW) learning model and Creative Problem Solving
KAPASITAS ADSORPSI ARANG AKTIF CANGKANG BINTARO (Cerbera odollam) TERHADAP ZAT WARNA SINTETIS REACTIVE RED-120 DAN REACTIVE BLUE-198 Aisyahlika, Siti Zaya; Firdaus, M. Lutfi; Elvia, Rina
Alotrop Vol 2, No 2 (2018)
Publisher : FKIP University of Bengkulu

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Abstract

The objective of this research was to utilize bintaro shell waste (Cerbera odollam). The morphology of bintaro shell is similar with coconut shell and the contains of lignin and cellulose is higher than coconut. Bintaro shell waste used as activated charcoal to remove environmental pollution caused by synthetic dyes waste of batik industry. The adsorbents were then applied to remove of Reactive Red-120 (RR) and Reactive Blue-198 (RB) dyes in aqueous solution using Visible Spectrophotometer analysis method. Bintaro shell was dried, cut and carbonized at 400°C for 1 hour, then activated with ZnCl2 20% for 24 hours at 27°C and dryed in oven at 105°C for 30 minutes. The activated charcoal of bintaro shell has proven afford to adsorbing RR and RB dyes. The optimum conditions (pH, contact time, adsorbent weight and temperature) were determined to obtain best adsorption capacity. The optimum of conditions for RR occured at pH 2, contact time of 40 minutes and adsorbent weight 100 mg while RB occurred at pH 11, contact time of 60 minutes and adsorbent weight 50 mg and with each the temperature 30°C. At optimum conditions the adsorption isotherm followed Freundlich model with maximum adsorption capacity obtained for RR and RB were 332.6 and 243.9 mg/g, respectively.
PERBANDINGAN HASIL BELAJAR KIMIA MODEL PEMBELAJARAN PROBLEM BASED LEARNING DAN THINK TALK WRITE Wahyuni, Nadya Dirma; Bahar, Amrul; Handayani, Dewi
Alotrop Vol 1, No 2 (2017)
Publisher : FKIP University of Bengkulu

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Abstract

[COMPARISON FROM LEARNING OUTCOMES OF PROBLEM BASED LEARNING MODELS AND THINK TALK WRITE  MODELS ]               Each learning model has advantages and disadvantages in every process.This research intent to know the difference student studying result on chemical learning among brazes that utilize learning model Problem Based Learning (PBL)  with class that utilize learning model Think is Write's Talc (TTW)  on jurisdictional material – chemical base law at class X SMA Negeri  10  Kota Bengkulu's . This research constitute quasi's experiment. Students learned result on observational it is seen from pretest's point and posttest difference. On class that utilize Problem Based Learning (PBL) model , increasing average value from student kognitiv as big as 49,23. Meanwhile class that utilize Think is Write's Talc (TTW) model ,  increasing average value learned student kognitiv as big as 56,33.   Hypothese  was tested by use of t test (? = 0,01) to result at t test  = 3,53 < t table  = 2,38. Research result to point out that are distinctive result  that significan among between class that utilize Problem Based Learning (PBL ) model and class that utilize Think is Write's Talk (TTW) model.
PEMANFAATAN EKSTRAK BUAH Morus alba L. (Murbei) SEBAGAI PENGAWET ALAMI IKAN Selaroides leptolepis (Selar) Nastiti, Diah Sari; Nurhamidah, Nurhamidah; Chandra, I Nyoman
Alotrop Vol 3, No 1 (2019)
Publisher : FKIP University of Bengkulu

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Abstract

The purpose of this study is to measure the influence of concentration and time of soaking of fruit extracts Morus alba l. (Mulberry) is effective as a preservative Selaroides leptolepis fish (Trevally). Samples taken of coral in the fruit of the Holy City of Argamakmur, North Bengkulu and trevally fish samples taken directly from the beach, the village Plow Jakat, province of Bengkulu. Fruit samples grinded using a blender and aqueous extracts are obtained through maceration method using aquades and filtered so that retrieved the mulberry and subsequent solution diluted with aquades be a concentration of 20, 40, 60 and 80% (v/v). Phytochemicals profile test to determination of secondary metabolites in extracts. The test is done through the methods of preserving this soaking on a several concentrations variation and soaking time with without soaking as control. The variation of the concentrations is done at a concentration of 10, 20, 30 and 40%, with soaking time variation 1, 2 and 3 hours. Variation of time observations were at 12, 18 and 24 hours and test the chemical content in the form of a test of water content, levels of Total Volatile Bases (TVB), and pH values. Phytochemical test results obtained the presence of saponins, alkaloids, terpenoids, phenolic and flavonoid compounds and do not contain steroids. The results showed that the extract of Mulberry fruits proved capable of lowering the pH and the levels of TVB but does not affect the water content of the fish. Soaking time variations do not affect the water content, pH and the levels of TVB. From the results obtained that the use of the mulberry fruit extract at concentrations of 30% with long submergence 1 hour most optimal for use as a preservative natural for S. leptolepis up to 18 hours at room temperature to the value pH 6.7 and TVB at 27.2 mg N%.
HUBUNGAN IMPLEMENTASI CONTEXTUAL TEACHING AND LEARNING (CTL) DENGAN HASIL BELAJAR SISWA MATA PELAJARAN KIMIA DI KELAS X MIA SMA NEGERI 8 KOTA BENGKULU Andiko, Pebri Tri; Rohiat, Salastri; Elvinawati, Elvinawati
Alotrop Vol 3, No 1 (2019)
Publisher : FKIP University of Bengkulu

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Abstract

This study aims to analyze the relationship of Contextual Teaching and Learning (CTL) implementation with students' learning outcomes in X class MIA SMA Negeri 8 Kota Bengkulu at 2017/2018 Academic year. This type of research is correlational research. The population in this research is class X MIA SMA Negeri 8 Kota Bengkulu 2017/2018 Academic year and research using total sampling technique where all population used also become sample of research with total 166 students. Data collection techniques in this study using questionnaires, observation sheets and students' chemistry learning results. Data analysis using Pearson correlational analysis and validation test, reliability, normality, linearity (with F test) , and hypothesis test. Based on the results of data analysis that has been done, obtained general conclusion of a positive relationship between the application of Contextual Teaching and Learning (CTL) with the results of students learningoutcomes in X class MIA SMA Negeri 8 Kota Bengkulu at 2017/2018 Academic year, indicated by the value rhitung obtained greater than the value of tabell r (0.704> 0.1281) with the level of correlation into the category of strong / high, it means there is a positive and strong relationship between the application of Contextual Teaching and Learning with student learning outcomesin X class MIA SMA Negeri 8 Kota Bengkulu at 2017/2018 Academic year.
UPAYA PENINGKATAN SENSITIVITAS NANOPARTIKEL PERAK UNTUK ANALISIS ION MERKURI(II) SECARA CITRA DIGITAL DENGAN PENAMBAHAN NaCl Prasetia, Edo; Firdaus, M. Lutfi; Elvinawati, Elvinawati
Alotrop Vol 3, No 2 (2019)
Publisher : FKIP University of Bengkulu

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Abstract

The very small concentration of mercury (Hg) in the environment is difficult to detect, so an accurate and sensitive method is needed in order to detect the concentration. Therefore, the purpose of this study was to develop an accurate and sensitive method based on the use of digital imaging methods and silver nanoparticles (AgNPs) as colorimetric sensors for mercury(II) ions (Hg2+) analysis. The process of making AgNPS is done by a bottom up method involving a reduction reaction. The precursor used is 1 mM AgNO3 solution and as bioreductor is an antioxidant compound present in extract of chili pepper (Capsicum frutescens L) with ratio 1: 9. Contact time variation 15, 30, 45, 60 min and 1, 2, 7 days. Addition of NaCl 0.5 and 1 M NaCl were used to increase the sensitivity of AgNPs as colorimetric sensors of Hg2+ ions. Digital Image Method is used to analyze Hg2+ ions at ppb concentration level. The results of the most optimum silver nanoparticles synthesized at the time of solar heating is 60 minutes. The addition of NaCl 0.5 M and 1 M into AgNPs is able to increase the sensitivity of AgNPs. Limit of Detection (LoD) of AgNPs added NaCl 0.5 M and 1 M was able to detect Hg2 + ions by 3.02 ppb and 2.46ppb.
SKRINING FITOKIMIA DAN AKTIVITAS ANTIOKSIDAN BEBERAPA FRAKSI DARI KULIT BATANG JARAK (Ricinus communis L.) Agustina, Wulan; Nurhamidah, Nurhamidah; Handayani, Dewi
Alotrop Vol 1, No 2 (2017)
Publisher : FKIP University of Bengkulu

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Abstract

[PHYTOCHEMICAL SCREENING AND ANTIOXIDANT ACTIVITY OF SOME FRACTIONS FROM BARK OF CASTOR (Ricinus communis L.)]. The Phytochemical screening was conducted to determine secondary metabolites found in the bark of castor (Ricinus communis L.).The test results of phytochemical screening that has been done presence of  phenolic, flavonoids, alkaloids, saponins, and terpenoids. Extraction is done by maceration using ethanol 96%. Tests performed on the fraction of the antioxidant activity of ethanol, ethyl acetate, n-hexane, and ascorbic acid as compared to using DPPH. The results of measuring the antioxidant activity using Uv-Vis Spectrophotometer IC50 values obtained succession namely fraction of ethanol, ethyl acetate, n-hexane, and ascorbic acid, 33,38, 24,38, 289, 05 and 12, 48 ppm. Fraction of ethanol and ethyl acetate has a very strong antioxidant activity due IC50<50 ppm while the n-hexane fraction very weak antioxidant activity. Phenolic and flavonoids the bark of castor that can be potentially as antioxidants
UJI EFEKTIFITAS ASAP CAIR CANGKANG BUAH KARET (Hevea braziliensis) SEBAGAI ANTIBAKTERI Bacillus subtilis Sari, Lia Retno; Sumpono, Sumpono; Elvinawati, Elvinawati
Alotrop Vol 3, No 1 (2019)
Publisher : FKIP University of Bengkulu

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Abstract

The purpose of this research was know the effectiveness quid smoke the liquid smoke of the rubber (Hevea braziliensis)  shell.The manifacture and purification of liquid smoke is carried out by 4 stages: pyrolysis, sedimentation, distillation, redestilate. The first of the research is calculating phenol levels, total acid, pH, and type weights The results showed that the feeding of rubber  (Hevea braziliensis) shell liquid Smoke proved to inhibit the growth of bacteria Bacillus subtilis where the higher the concentration of liquid smoke, the greater the resistance. The phenol levels contained in the liquid smoke of the rubber shells were obtained at 0.84% with a total acid rate of 4.725%, and a  pH at  2.548 and a density at 1.004. Antibacterial test using disc paper with see diameter clear zone. Bacterial using is pure cultur Bacillus subtiis bacteria. The concentration liquid smoke to antibacteral test is 5%, 10%, 15%, 20% and 25%. Of the five treatment obtained KHM 20% with diameter clear zone is 5,21 mm. Analysis results using One Way ANOVA obtained F hitung ? f tabel then there Significant differences Against the resulting clear zone.
PENERAPAN MODEL PEMBELAJARAN MENCARI PASANGAN DAN BERTUKAR PASANGAN DALAM KELOMPOK DISKUSI TERHADAP HASIL BELAJAR SISWA PADA MATERI SISTEM KOLOID KELAS XI IPA MAN 1 KOTA BENGKULU Aprianika, Sella; Bahar, Amrul; Rohiat, Salastri
Alotrop Vol 3, No 1 (2019)
Publisher : FKIP University of Bengkulu

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Abstract

This study aims to determine differences in student learning outcomes using a model of learning make a match with a model partner switch the subject matter colloidal system class XI IPA MAN 1 Bengkulu City in the academic year 2017/2018. The research population of all classes XI IPA amounted to 4 classes with a total population of 151 students. The sampling of the research was done by normality test and homogeneity test before the study population. Obtained a sample of research that consists of 2 classes of class XI IPA 1 as an experimental class I that apply the model make a match and class XI IPA 2 as an experimental class II using a model parten switch. Student learning outcomes are seen from the postest score. Students' learning outcomes in the make a match class had an average of 82.714 while in the partner switch the average pair was 77.5. This shows that the model of make a match is more effectively used in the process of learning in class than the model of partner switch. From the t test-t test on both experiment classes is obtained tcount and ttable = 1.707> 1.666 (? = 0,05). The results show that H0 is rejected and Ha is accepted which means that there is a significant difference between the learning result of the students using make a match model and the learning model partner switch on the material of the colloidal system.

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