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Alotrop Jurnal Pendidikan dan Ilmu Kimia
Published by Universitas Bengkulu
ISSN : 22528075     EISSN : 26152819     DOI : -
Core Subject : Science, Education,
Chemistry Education
Welcome to the Journal Alotrop, is an Open-Acces and peer-reviewed journal aims to publish scientific articles related to chemistry and education :i.e an interaction between natural sciences, educational sciences, technologies and management for both education and sciences and wise use of resources. We particularly encourage manuscripts that discuss contemporary research that can be used directly or inderecly in adressing critical issues and sharing of advanced knowledge and best practices in chemistry and education.
Arjuna Subject : Kimia(semua kategori) - Kimia (Lain-Lain)
Articles 218 Documents
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IMPLEMENTASI MODEL PEMBELAJARAN LEARNING CYCLE 5E PADA MATERI HIDROLISIS GARAM DI KELAS XI MIPA SMAN 1 BENGKULU TENGAH TAHUN AJARAN 2018/2019 Isnaini Safitri; Dewi Handayani; Salastri Rohiat
ALOTROP Vol 3, No 2 (2019)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v3i2.10507

Abstract

This study aims to determine the effect of the implementation of the 5E Learning Cycle learning model on increasing mastery of concepts in the subject matter of salt hydrolysis. This research was conducted at SMAN 1 Bengkulu Tengah in the 2018/2019 class XI MIP academic year in one meeting. The trial implementation of the 5E Learning Cycle model uses a pre-experimental research design with the form of one-group pretest-posttest design. The study was  conducted in February 2019 at SMAN 1 Bengkulu Tengah. The population in this study were students of class XI MIPA in SMA Negeri 1 Bengkulu Tengah academic year 2018/2019 which amounted to 126 people. Determination of the study sample was carried out by testing the normality of the population. The study sample was taken using simple random sampling technique obtained by students of class XI MIPA 1, the number of students was 31 people. The instruments used consisted of student response questionnaire sheets and concept mastery assessment sheets. Student response data, mastery of concepts were analyzed descriptively and their improvement was analyzed by analysis of gain scores. The results showed that students gave a positive response to the 5E learning cycle model with an average value of 4.2 from a maximum value of 5 which indicated that students felt greatly helped by learning with the 5E Learning Cycle model. This is also supported by a high score increase on mastery of concepts which obtained an average value of 76.97 which is in the effective category. Based on the results of the study, it was concluded that the implementation of the 5E learning cycle model in the subject matter of effective salt hydrolysis to improve mastery of concepts in class XI MIPA SMAN 1 Bengkulu Tengah Academic Year 2018/2019.
KARAKTERISASI ADSORBEN KARBON AKTIF DARI SABUT PINANG (Areca catechu ) TERHADAP KAPASITAS ADSORPSI ZAT WARNA INDIGOSOL BLUE 04-B Ahmad Fitriansyah; Hermansyah Amir; Elvinawati Elvinawati
ALOTROP Vol 5, No 1 (2021)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v5i1.16485

Abstract

UJI AKTIVITAS ANTIOKSIDAN DAN ANTIBAKTERI EKSTRAK DAUN Ricinus communis L (JARAK KEPYAR) Julia Sarfina; Nurhamidah Nurhamidah; Dewi Handayani
ALOTROP Vol 1, No 1 (2017)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v1i1.2725

Abstract

This study aims to determine the antioxidant activity of jarak kepyar’s  leaf extracts (Ricinus communis L.) and to determine of the fraction the growth of Erwinia carotovora. Jarak kepyar’s leaf extracted by maceration method using ethanol and fractionated using n-hexane and ethyl acetate. Antioxidant test using DPPH (1,1-diphenyl-2-picrylhydrazyl) with various concentrations of 125 ppm, 100 ppm, 75 ppm, 50 ppm, 25 ppm, 15 ppm and 5 ppm. Antibacterial test conducted on the active fractions as antioxidants using paper disc method and variations in the concentration of 1000 ppm, 500 ppm, 250 ppm, 125 ppm, 62.5 ppm. Phytochemical test results jarak kepyar’s leaf contain secondary metabolites are alkaloids, flavonoids, phenols and terpenoids. The test results demonstrate the antioxidant activity of ethyl acetate fraction is very strong as an antioxidant with IC50 values of 5.4 ppm and a strong ethanol fraction categorized as antioxidants IC50 of 99.8 ppm. Antibacterial test results showed inhibition of the leaf fraction of  jarak kepyar’s (Ricinus communis L.) against Erwinia carotovora categorized weak growth in ethanol fractions with inhibition zone diameter of 4 mm and being in ethyl acetate fraction with a diameter of 5 mm
PEMBUATAN DAN KARAKTERISASI METIL SELULOSA DARI BONGGOL DAN KULIT NANAS (Ananas comosus) Lena Rahmidar; Seruni Wahidiniawati; Tety Sudiarti
ALOTROP Vol 2, No 1 (2018)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v2i1.4807

Abstract

[MAKING AND CHARACTERIZATION OF CELLULOSE METHOD OF BONGGOL AND LEATHER LEATHER (Ananas comosus)] Wastes of core and  peel of pineapple are often not utilized properly, in fact the waste has nutritional content that can be useful. Carbohydrate content in the waste is large enough and allows to be utilized. The purpose of this research is for converting glucose into cellulose and synthesized into methylcellulose. The first stage is glucose from core and peel of pineapple converted into microbial cellulose with Acetobacter xylinum bacteria with the addition of nitrogen and carbon sources. The second stage is synthesis of methylcellulose with methylene chloride and the solvent aquadest/acetone. The dried microbial cellulose was firstly swelled with NaOH addition, then methylation by addition of solvent and methylene chloride and then refluxed at 50-60. Then methyl cellulose neutralized, washed and dried at 50.The FTIR results showed typical cellulose uptake for cellulose microbial pineapple core at wave number 3377.36 cm-1 for OH bonds and 2935.66 cm-1 for CH bonds and in cellulose microbialpineapple peel at wave number 3377.36 cm-1 for OH bonds and 2935.66 cm-1 for the CH bonds. The ratio OH/CH of methyl cellulose-acetone has a smaller value in the core and peel of pineapple concluded that acetone is more efficient to use as a solvent at the methylation. The substitution value of the core and peel of pineapple skin is estimated to below based on the solubility test results.
STUDY ON Hibiscus tiliaceus LEAVES AS ANTIBACTERIAL AND ANTIOXIDANT AGENTS Mohamad Syahmie Samsudin; Yosie Andriani; Purbowatiningrum Ria Sarjono; Desy Fitrya Syamsumir
ALOTROP Vol 3, No 2 (2019)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v3i2.9874

Abstract

This study aimed to evaluate antioxidant and antibacterial activities of methanol, hexane, dichloromethane, ethyl acetate, and water crude sample fractions of H. tiliaceus leaves. Various type of samples play an important role to determining which compound that will give the positive results in antioxidant test (inhibiting free radical scavenging activity) which they probably have potency for preventing the cancer disease. Furthermore, those types of samples were also tested to the antibacterial test as their possibilities to be created as new antibiotics in the future. This research also focused on what compound groups that actually present in H. tiliaceus leaves by using the phytochemistry test. Antioxidant potency of H. tiliaceus leaves extracts for the radical scavenging activity for quantitative assay was measured by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. The antibacterial potency was measured by the Muller Hinton Agar (MHA) by applied the sample chemical crude in the plate. The result showed that all chemical crude of H. tiliaceus leaves has high antioxidant property as methanol crude (MC) 308.416%; hexane crude (HC) 232.837%; dichloromethane crude (DC) 150.837%; ethyl acetate crude (EC) 73.623% and water crude (WC) 71.777% with respected to the readings of  100% from quercetin (Q) as a positive control. From antibacterial result, entire samples had shown the positive results towards both gram positive (Staphylococcus aureus and Bacillus subtilis) and gram negative bacteria (Klebsiella pneumonia and Escherichia coli). The ranges of the inhibition zone were both at 7-10 mm and 10-15 mm. The phytochemistry test determine that the samples actually contained a lot of compounds which were proteins, carbohydrates, phenols/tannins, flavonoid, terpenoids, glycosides and also steroid. It is clearly indicated that H. tiliaceus leaves have potential to be used against the antioxidant and also as new antibacterial agents
PERBANDINGAN MODEL PEMBELAJARAN PROBLEM SOLVING DAN PROBLEM BASED LEARNING TERHADAP KEMAMPUAN BERPIKIR KRITIS SISWA KELAS XI MIA MAN 2 KOTA BENGKULU Ida Nurjelita Sani; Amrul Bahar; Elvinawati Elvinawati
ALOTROP Vol 4, No 2 (2020)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v4i2.13834

Abstract

The aim of this study to determine the comparison of Problem Solving (PS) and Problem Based Learning (PBL) models to critical thinking skills of student on buffer solution material. This type of research is quasi experimental research with posttest only control group design research design. The population of this study is all class XI IPA of MAN 2 Bengkulu City academic year 2018/2019 as many 133 students. The analysis of the data was used the normality test,  homogeneity test, and hypothesis test.  The research sample was taken by purposive sampling technique. Data on the results of students' critical thinking skills are obtained from the value of the posttest or final test. Posttest is done by using test instruments in the form of descriptive tests as many as 6 items, each of which has a different critical thinking indicator. Previous test instruments were tested and analyzed to see the level of validity, reliability, differentiation and the level of difficulty of the questions. The results of the study showed that the average value of students' critical thinking ability achievement in the experimental class 1 was higher than that of the experimental class 2 students which were 74.09 and 70.22. Based on these results, the experimental class 1 which applied the problem solving learning model was better at improving students' thinking skills than the experimental class 2 which applied a problem-based learning model. Hypothesis testing with the T-test at the 0.05 significance level yields a sig value. (2-tailed)> level of signicant which is 0.147> 0.05 so that Ho is accepted. Thus, it can be concluded that there is no significant difference between the critical thinking skills of the experimental class 1 students who apply PS models and experimental class 2 students who apply the PBL model.
AKTIVITAS ANTIOKSIDAN DAN ANTIBAKTERI EKSTRAK DAUN Jatropha gossypifolia L Nia Sapitri Pangestu; Nurhamidah Nurhamidah; Elvinawati Elvinawati
ALOTROP Vol 1, No 1 (2017)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v1i1.2707

Abstract

This study was conducted to determine the activity of Jatropha gossypifolia L (jarak merah’s) leaf extract as an antioxidant and antibactery against acne causing bacteria (Propionibacterium acnes). To obtain an J. gossypifolia L jarak merah’s leaf extract by maceration using 96% ethanol, and then fractionated with n-hexane and ethyl acetate. Testing of antioxidant activity by DPPH method and antibactery activity test by the paper disc method. Antioxidant activity test has done for ethanol fraction, ethyl acetate fraction and n-hexane fraction, while testing for antibacterial activity performed on fractions active as antioxidant. The test results demonstrate the antioxidant activity of ethyl acetate fraction and the ethanol fraction as a fraction very strong with IC50 value of 22.33 ppm for ethyl acetate fraction and 41.04 ppm for ethanol fraction. Then the fraction of ethyl acetate and ethanol fraction antibactery activity test, the result is known that both factions have the ability to inhibit the growth of bacteria Propionibacterium acnes demonstrated by the inhibition zone is formed. In 1000 ppm is formed diameter of the greatest inhibition zone that is equal to 6 mm for ethyl acetate fraction and 5 mm for ethanol fraction.
ANALISIS KEMAMPUAN BERPIKIR KRITIS MATA PELAJARAN KIMIA PADA SISWAKELAS XI IPA SMAN 1 KEPAHIANG Selly Yunita; Salastri Rohiat; Hermansyah Amir
ALOTROP Vol 2, No 1 (2018)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v2i1.4628

Abstract

[ANALYSIS OF THE CRITICAL THINKING ABILITY FROM CHEMICAL SUBJECTS IN STUDENTS OF CLASS XI IPA SMAN 1 KEPAHIANG] This research aims to know the critical thinking ability of students. Type of this research is descriptive research using quantitative methods. This research was carried out in SMA Negeri 1 Kepahiang on September 2 to 8 may in 2017. The population in this research is the entire class XI IPA are registered on the even-numbered school year 2016/2017 semester. As the samples are taken at class XI IPA 6 of 32 participants.  Data collection is done with the test in the form of reserved descriptions as much as 10 round the whole includes indicators of critical thinking from the taxonomy of Bloom that is level (C2) understand (C3), apply (C4), analyzing and evaluating (C5). Test results obtained from the analysis of results the percentage of students with the ability to answer a question of thinking very critically at 15,6%, quite critical at 53,2 %, and less critical at 31,2 %, with an average value of 61.81. From the average of the values obtained showed that students who have average value included in the category of being. Based on the analysis of the data collected can be inferred levels of critical thinking ability of the students in class XI IPA 6 SMA Negeri 1 Kepahiang at school 2016/2017 academic year can be grouped in a category group are of 53,2 %, middle , 15,6 %  at high group and 31,2 % at low groups. From the results, it can be concluded that overall students in grades at  XI IPA 6 SMA Negeri 1 Kepahiang even 2016/2017 academic year with the ability to enough think critically.
Studi Komparasi Motivasi Belajar Kimia Siswa Kelas X Program Peminatan dan Lintas Minat di MAN 2 Kota Bengkulu Elinge Haster; Salastri Rohiat; Sumpono Sumpono
ALOTROP Vol 3, No 1 (2019)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v3i1.9039

Abstract

The purpose of this research was to measure differences chemistry learning motivation of tenth grade students class at major (MIPA) and cross-major (IPS) courses in MAN 2 Bengkulu city. The population in this research is 260 students from 8 classes consisting of four MIPA classes and four IPS classes and also become sample in this research. The type of this research is quantitative descriptive that aims to provide a description of the variables of learning chemistry motivation in the class of major (MIPA) and cross-major (IPS) and emphasize the analysis on data figures obtained by statistical methods. Chemical learning motivation data obtained from the results of a questionnaire motivation to learn chemistry. Questionnaire of motivation to learn chemistry consists of 61 items that validity tested by using SPSS (Statistical Package for the Social Sciences) program to obtain 54 valid items and 7 invalid items and tested reliability with Cronbach's Alpha value of 0.897 and this questionnaire is stated reliable. The research questionnaires were analyzed using normality test, homogeneity test and hypothesis test. The average value of students' learning motivation of major (MIPA) and cross-major (IPS) in chemistry subjects was 197.19 and 189.71 in the good category. The hypothesis testing by using the test T 0.05 at significant level, then it was gained value namely 2.8027 > 1.6508. The results showed that there is a significant difference between major courses and cross-major courses in the chemistry learning motivation of tenth grade students. Motivation to learn chemistry in the major courses better than cross-major courses.
IMPLEMENTASI KURIKULUM 2013 BAGI GURU KIMIA DI SMA NEGERI SEKOTA BENGKULU Ahaky Roza Clorawati; Salastri Rohiat; Hermansyah Amir
ALOTROP Vol 1, No 2 (2017)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v1i2.3535

Abstract

[IMPLEMENTATION OF 2013 CURRICULUM FOR CHEMICAL TEACHERS IN SMA Negeri AT BENGKULU ] This research is a description research conducted from SMA Negeri 1 to SMA Negeri 10 Kota Bengkulu for chemistry teacher in 2016/2017 academic year. This study aims to describe the implementation of the 2013 curriculum for chemistry teachers in the SMA Negeri in Bengkulu City. The population of this research is all the chemistry teachers who teach in ten SMA Negeri in Bengkulu consisting of 42 teachers. Samples were taken by proportional random sampling technique as much as 20%, but the samples taken are teachers who have implemented the curriculum 2013. Obtained final sample of 26 teachers. In this study, a questionnaire was used to collect data, including indicators of the overall implementation of the curriculum, scattered on 53 points of statement, using Likert Scale with a score of 1 to 4. which was then processed using Statistical Product Service Solution(SPSS)16 program. The results showed that the implementation of the 2013 curriculum, the average percentage of teachers who have implemented is 66.67% with the category mostly implemented. Specifically that is, planning obtained at 65,385%, implementation obtained at 57,692%. and assessment of learning result obtained at 76,923% with category mostly executed.

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