56 research outputs found
THE USE OF ICT-BASED MEDIA IN WEB-BASED COLLABORATIVE ASSISTANCE OF HYBRID LEARNING ON CHEMICAL KINETIC TO IMPROVE STUDENTSā ACADEMIC PERFORMANCE
This research studied the implementation of web-based assistance using opened source Learning Management System (LMS), completed by other learning media on Chemistry, such as e-book and video at Chemistry Education Department, UNY, and its effect to studentsā achievement, learning independence and discipline. Delivery system of learning Chemical Kinetic was carried out by hybrid learning, the. combination between face-to-face and online learning. Online learning was provided as enrichment and assistant supports. Not only are students able to join in online learning, but also parents are. The samples of this research were students attending the lecture of Chemical Kinetics at UNY. Due to the use of web-based assistance, the improvement of studentsā achievement, and studentsā responses towards their learning independence and discipline were measured. This research showed that Chemistry learning media including video, e-book that accompanying the LMS were good in quality based on the review of students and Chemistry lecturers of UNY. Students strongly agreed with the advantages of LMS for hybrid learning of Chemical Kinetic, and they did not face significant constraint with internet connection whether at home or campus. Students strongly agreed that this hybrid learning can improve their learning independence and discipline. Whereas, parents supported the use of hybrid learning of Chemical Kinetic and stated that they were able to accompany and to guide students effectively in learning. Moreover, this research showed that by the use of hybrid learning on Chemical Kinetic, studentsā cognitive achievement increased significantly
MEMAHAMI PROSES SORPSI ION FOSFAT OLEH GOETHITE DAN MONTMORILLONITE
Sorpsi Ion fosfat oleh monmorillonit pada suhu 30 oC telah dipelajari dan dilaporkan sebelumnya sebagai rangkaian kegiatan penelitian ini. Hasil penelitian tersebut melaporkan bahwa fosfat mengikat monmorilonit dengan membentuk dua kompleks outer sphere dengan menggunakan ikatan hydrogen. Karena suhu merupakan faktor yang berpengaruh dalam adsorpsi, maka reaksi-reaksi yang berlangsung pada adsorpsi ion fosfat dengan suhu yang berbeda; 10 oC dan 50 oC perlu diteliti. Penelitian ini dilaksanakan dengan tujuan untuk menentukan parameter termodinamik untuk reaksi kompleksasi permukaan pada adsorpsi ion fosfat oleh monmorilonit.
Data penelitian dikumpulkan melalui eksperimen adsorpsi pada suhu 10 dan 50 oC. Eksperimen tersebut meliputi eksperimen adsorpsi tepi (adsorpsi sebagai fungsi pH), isotherm adsorpsi (adsorpsi sebagai fungsi konsentrasi fosfat), titrasi asam-basa (suatu titrasi untuk mengetahui jumlah ion H+ yang ditangkap atau dilepas di saat terjadi reaksi permukaan), dan kinetika desorpsi. Analisis data dilakukan dengan menggunakan model kompleksasi permukaan untuk konfirmasi hasil penelitian sebelumnya (Jaslin et al. submitted), serta untuk menentukan harga ĪH dan ĪS.
Harga ĪH untuk reaksi pertama dan kedua berturut-turut adalah 39,756 dan 3,765x10-7 kJ molā1. Kedua reaksi mempunyai harga ĪH positif yang berarti reaksi berlangsung secara endotermik. Energi yang besar dalam reaksi pertama dibutuhkan oleh situs Xā untuk desolvasi parsial oleh situs tersebut dalam proses protonasi, di mana H+ menggantikan K+ atau kation permukaan lain untuk selanjutnya berinteraksi dengan ion fosfat. Harga āH untuk reaksi kedua yang kecil mengindikasikan bahwa ikatan hidrogen dalam kompleks yang terbentuk di reaksi kedua ini mudah terlepas kembali. Harga ĪS untuk reaksi pertama dan kedua berturut-turut adalah122,523 dan 2,393 x10-2 J Kā1 molā1. Harga ĪS yang melebihi -10 kJ molā1 merupakan suatu indikator bahwa kedua reaksi berlangsung melalui mekanisme reaksi disosiatif.
Kata kunci: fosfat; monmorilonit; kompleks outer-sphere; model kompleksasi permukaan; entalpi; entropi; mekanisme reaksi disosiasi
FMIPA, 2007 (PEND. KIMIA
THE USE OF HYBRID MULTIMODAL LEARNING ON CHEMISTRY AT SENIOR HIGH SCHOOL TO IMPROVE STUDENTSā MOTIVATION
Integration of delivery systems of learning such as model, method and media in teaching-learning in this research was called multimodal learning. This research investigated the effect of multimodal learning to studentsā motivation. Multimodal learning in this research was cooperative learning delivered through hybrid, a combination between face-to-face and online using learning management system (LMS) Edmodo, and completed by some multimedia. Samples of this research were students of Grade XI-Science of SMAN 1 Purworejo in the academic year of 2013/2014. The samples were from two groups, experiment and control. Data of studentsā motivation from both groups were collected using a questionnaire and analyzed using independent sample t-test to study the difference of studentsā motivation between the groups, and using paired t-test to investigate the improvement of studentsā motivation in each group. The results showed the improvement of studentsā motivation from experiment group was higher significantly than that from control one (sig/ p = 0,000). The motivation of student from experiment group improved significantly due to multimodal learning (sif/p = 0,000), but that from control group did not improved significantly (0,054)
Enhancing Studentsā Conceptual Understanding and Learning Independence in Chemical Equilibrium using E-Module Based Guided Discovery Learning
Chemical equilibrium is considered abstract so it requires visualization by analogy through electronic modules combined with interactive multimedia teaching materials. This study aims to examine the influence of a guided discovery learning-based e-module on chemical equilibrium on the development of conceptual understanding and self-directed learning among 11th grade science students enrolled in the control and experimental groups. The research framework employed in this study follows a research and development (R&D) model. The participants were selected using the cluster random sampling technique. The e-module, developed based on GDL principles, was administered to 72 science 11th grade students through a quasi-experimental design involving a posttest-only control group. The research employed conceptual understanding test of chemical equilibrium and a self-directed learning questionnaire as data collection instruments. The disparities in conceptual understanding and self-directed learning between the control and experimental groups were assessed using the MANOVA (Hotteling's trace) test. There is a significant difference in both the overall and individual abilities of conceptual understanding and learning independence between students who used electronic modules based on GDL and those who did not, as indicated by simultaneous significance levels of 0.001 and individual significance levels of 0.009 and 0.004, all of which are smaller than 0.05
THE USE OF WEB-BASED ASSISTANCE IN MULTIMODAL CHEMISTRY LEARNING AT SENIOR HIGH SCHOOL TO IMPROVE STUDENTSā MOTIVATION
The development of information and communication technology (ICT) affects significantly education sector. Nowadays, students are very familiar with ICT, such as computer and Internet which has the advantage to use as media in chemistry learning. The use of student-friendly application of a web based learning management system (LMS) that completed by chemistry multimedia can be benefit for chemistry learning because the multimedia in the web can be accessed anywhere at any time as potential assistance for students. Learning was managed through various learning strategies in the combination of web-based assistance and face-to-face learning in cooperative model of student team achievement division (STAD) which called multimodal learning. This research investigated the effects of multimodal learning on chemistry towards studentsā motivation. This research was an experimental research to measure the improvement of students motivation due to multimodal learning. The samples of this research were 2 groups of students, which are experimental group consisting of 30 students and the control group having 31 students. Samples were from grade X of SMA N 7 Purworejo. The difference of chemistry learning between students from the experimental group and control group was learning with and without multimodal learning, respectively. The students' motivation was collected using a questionnaire, observation, and analyzed statistically. Studentsā motivation from one group was compared to the another group using independent sample t-test, and the improvement of studentsā motivation was analyzed using paired-sample t-test. The result of this research showed that studentsā motivation of group with multimodal learning was higher significantly than that without multimodal learning
STUDI TENTANG SORPSI ION FOSFAT OLEH GOETHITE
Penelitian ini bertujuan untuk mempelajari reaksi pada proses adsorpsi ion fosfat oleh goethite, menentukan konstanta kesetimbangan reaksi-reaksi tersebut dibandingkan dengan adsorpsi oleh montmorillonite.
Goethite merupakan metal hidroksida yang memiliki situs aktif sebagai akibat dari keberadaan gugus fungsi hidroksil (SOH) yang dapat terprotonasi dan terdeprotonasi oleh derajat keasaaman sistem. (situs SOH). Berbeda dengan montmorillonite, yang selain memiliki situs aktif tersebut, montmorillonite juga memiliki situs bermuatan negatif permanen (Situs Xā), dan permukaan internal (daerah antar lapis) yang juga selalu bermuatan negatif (Xā) sebagai akibat pergantian isomorfik.
Data penelitian ini dikumpulkan melalui eksperimen adsorpsi tepi untuk menentukan pengaruh pH, isoterm adsorpsi untuk menentukan pengaruh konsentrasi sorbat, dan titrasi asam-basa untuk menentukan banyaknya ion H+ yang diikat atau dilepaskan pada proses adsorpsi. Ketiga set eksperimen tersebut masing-masing dilakukan pada suhu 10, 30, dan 50 oC. Data titrasi selanjutnya dimodel menggunakan model Kapasitan Konstan (Constant Capacitance -Surface Complexation Model (CCM)) dan Kapasitan Konstan Modifikasi (Extended Constant Capacitance Model-Surface Complexation Model (ECCM)) untuk memprediksi reaksi-reaksi adsorpsi dan menentukan konstanta kesetimbangan reaksi-reaksi tersebut.
Parameter tersebut selanjutnya dijadikan parameter tetap dalam membuat fit terhadap data adsorpsi tepi, yang ternyata fit dengan baik, yang berarti parameter hasil pemodelan adalah baik, dan dapat diterima.
Model kompleksasi permukaan menunjukkan bahwa ion fosfat terikat oleh permukaan goethite dengan membentuk dua kompleks Ā¬inner-sphere. Kompleks pertama, terbentuk pada pH rendah antara ion fosfat dengan situs SOH yang terprotonasi melalui ikatan hidrogen, mengikuti reaksi:
SOH + 2 H2Lā[SOH2+ ā (H2L)2ā2]ā
Kompleks kedua terbentuk pada pH tinggi antara ion fosfat dengan gugus SOH yang juga melalui ikatan hidrogen, mengikuti reaksi:
SOH + H2Lā [(SOH) ā [H2L]ā]ā
Kata kunci: goethite; fosfat; kompleks inner-sphere; model kompleksasi permukaan.
FMIPA, 2008 (PEND. KIMIA
Development of Guided Inquiry-Based Electronic Modules and Its Effects on Students' Chemical Literacy
One effort to present abstract concepts is the use of learning media. Electronic can provide opportunities for students to learn independently without relying on them. This study aims to determine the feasibility and practicality of guided inquiry-based electronic modules, the difference in studentsā chemical literacy abilities in each class, and the effectiveness of learning using guided inquiry-based electronic modules on studentsā chemical literacy. This research is a 4D development model consisting of Define, Design, Develop, and Disseminate. This study was conducted at Senior High School 1 Tembilahan Hulu, and the participants were 60 high school students and five chemical teachers, and two validatorsā data collection in questionnaires and tests. This study used a quasi-experimental method and a post-test-only control group design. The data analysis technique in this research is a descriptive statistical analysis technique of percentages. The results showed that the feasibility of the product assessed by validators showed that the guided inquiry-based electronic module was proper to use in this research. The practicality of the chemistry teacher assessment shows a very good category, the chemical literacy of students who use guided inquiry-based electronic modules in learning is better than students who do not use guided inquiry-based electronic modules in learning. The effectiveness test showed that learning using an electronic module based on guided inquiry scored 0.74 in the medium category
Supporting Studentsā Basic Science Process Skills by Augmented Reality Learning Media
Science process skills (SPS) are one of the skills needed in the chemistry learning process, in order to gain a complete understanding of the concepts. This skills categorized into two types; basic and integrated. This research aimed to develop a product of Augmented Reality (AR) learning media then to know its feasibility, practicality, and effectiveness on studentsā basic SPS on acid base learning. The research adopted Research and Development (R&D) with 4-D model consisted of define, design, develop, and disseminate stages. Questionnaire was used to measure the feasibility and practicality. Then, the obtained data were analyzed by qualitative and quantitative descriptive. In addition, SPS test was used to measure the effectiveness of AR learning media and the data were analyzed by the test of One-way ANOVA, Tukeyās Post Hoc test, and General Linear Model (GLM) Univariate. The result showed that the AR learning media is feasible, practical, and effective with big influence to support studentsā basic SPS on acid base learning
PENGARUH TAWAS HASIL SINTESIS DARI LIMBAH KALENG MINUMAN TERHADAP KINETIKA ADSORPSI METHYL ORANGE OLEH KAPAS DAN SERAT KAIN
Penelitian ini bertujuanuntuk menentukan order reaksi dan konstanta laju reaksi
pada pengikatan zat warna azo methyl orange oleh adsorben kapas dan kain. Selain
itu, pengaruh penambahan mordan tawas hasil sintesis dari kaleng bekas terhadap
konstanta laju pengikatan juga diteliti. Data dikumpulkan melalui kinetika adsorpsi,
yaitu pengukuran konsentrasi methyl orange yang terikat olehadsorben sebagai
fungsi waktu danadsorpsi tepi,untuk menentukan pengaruh pH terhadap adsorpsi.
Hasil adsorpsi tepi dimanfaatkan untuk menentukan pH optimal dan untuk
keperluan pengontrolan pH dalam kinetika adsorpsi. Semua eksperimen tersebut
dilakukan pada suhu 30
o
C, dandata yang terkumpul dianalisis dengan menggunakan
persamaan laju reaksi Lagergren. Hasil analisis data menunjukkan bahwa pengikatan
methyl orange baik oleh kapas maupun kain berlangsung melalui reaksi berorder
dua. Konstanta laju reaksi pengikatan methyl orange oleh kapas tanpa dan dengan
penambahan tawas sintesis berturut-turut adalah 93,669 dan 476,858 g mmol
menit
-1
. Sedangkan konstanta pada pengikatan zat warna tersebut oleh kain tanpa
dan dengan penambahan mordan sintesis berturut-turut adalah -79,436 dan -78,520g
mmol
-1
menit
-1
. Penambahan mordan hasil sintesis kaleng bekas dapat mempercepat
terwujudnya kesetimbangan reaksi pengikatan oleh kapas, tetapi tidak berpengaruh
pada pengikatan kain
Validity and Reliability Test of the Learning Independence Questionnaire Instrument in Using Electronic Modules
This research aims to create an instrument that can measure students' learning independence by measuring the level of validity and reliability. The instrument is a questionnaire for student learning independence consisting of 41 statements (20 positive statements and 21 negative statements) with responses based on a Likert scale score of 1 to 5. The research location for the empirical test of learning independence was at SMAN 1 Kalasan class XII MIPA in 3 classes. The number of empirical trial participants was 99 students. The results of the empirical test of the learning independence questionnaire instrument were then analyzed using the Winstep Rasch model program. The quality of the instrument can be determined from the unidimensional assumption test, the suitability test of the statement items to the Rasch model (item fit), and the bias of the statement items with the help of the Winstep program. The results obtained were that in the validity calculation there was 1 invalid statement out of 41 existing statements, namely the statement "I try to study as best as possible to achieve good performance" on the responsibility indicator. The reliability of the learning independence questionnaire instrument regarding the use of electronic modules is 0.93 and is in the very high category, so it can be concluded that the other 40 statements are declared valid and variable so that they can be used as instruments in measuring learning independence regarding the use of electronic modules.Penelitian ini bertujuan untuk membuat instrumen yang dapat mengukur kemandirian belajar peserta didik dengan mengukur tingkat validitas dan realibilitasnya. Instrumen berupa angket kemandirian belajar peserta didik yang terdiri dari 41 pernyataan (20 pernyataan positif dan 21 pernyataan negatif) dengan respon berdasarkan skala likert skor 1 sampai 5. Hasil yang diperoleh yaitu pada perhitungan validitas terdapat 1 pernyataan yang tidak valid dari 41 pernyataan yang ada yaitu pernyataan āSaya berusaha belajar sebaik mungkin untuk mencapai prestasi yang baikā pada indikator tanggung jawab. Realibilitas instrumen angket kemandirian belajar terhadap penggunaan modul elektronik sebesar 0,93 dan termasuk kategori sangat tinggi, sehingga dapat disimpulkan bahwa 40 pernyataan lainnya dinyatakan valid dan variabel sehingga dapat digunakan sebagai instrumen dalam mengukur kemandirian belajar terhadap penggunaan modul elektronik
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