Dampak Pembelajaran Process Oriented Guided Inquiry Learning Terhadap Pengetahuan Metakognitif Siswa Pada Topik Kesetimbangan Kelarutan

<p><strong>Abstract:</strong> The aim of this study is to investigate the difference of XI grade science students’ metacognitive knowledge as the impact of POGIL and verification learning on solubility equilibrium topic. The study used quasy experiment design. Analysis is done using Mann-Whitney U test at 5% significance. The result showed that there is difference on students’ metacognitive knowledge who are taught by POGIL and verification learning. The students who are taught by POGIL have higer metacognitive knowledge than that of are taught by verification learning.</p><strong>Abstrak:</strong><em> </em>Penelitian ini bertujuan untuk mengetahui perbedaan pengetahuan metakognitif siswa kelas XI IPA sebagai dampak dari pembelajaran POGIL dan verifikasi pada topik kesetimbangan kelarutan. Desain penelitian yang digunakan adalalah <em>quasy experiment</em>. Analisis dilakukan dengan menggunakan uji <em>Mann-Whitney U </em>pada taraf signifikansi 5%. Hasil penelitian menunjukkan terdapat perbedaan pengetahuan metakognitif antara siswa yang dibelajarkan dengan menggunakan pembelajaran POGIL dan verifikasi. Siswa yang dibelajarkan dengan POGIL memiliki pengetahuan metakognitif lebih tinggi dibandingkan siswa yang dibelajarkan dengan pembelajaran verifikasi.

Process Oriented Guided Inquiry Learning dalam Mereduksi Miskonsepsi Siswa SMA pada Materi Kesetimbangan Kelarutan

The application of the Process Oriented Guided Inquiry Learning (POGIL) strategy was carried out to reduce students' misconceptions on solubility equilibrium material. The design of this experimental study was a randomized control group pretest-posttest. The evaluation instrument used is a three-tier multiple-choice test using the Certainty of Response Index. The population of this study was 11-grade students one of the public schools in Pekanbaru city. The study sample was determined randomly after the normality test and homogeneity test was carried out. The experimental class was treated with the application of the POGIL learning strategy while the control class was without the implementation of the POGIL strategy. Data analysis for hypothesis testing is done using the right-party t-test. The results showed that tcount <ttable (-0.59 <2.02) can be interpreted that the application of the POGIL strategy can reduce students' misconceptions in the solubility equilibrium material with a reduction in misconceptions by 47.05%.Abstrak:Penerapan strategi Process Oriented Guided Inquiry Learning (POGIL) dilakukan untuk mereduksi miskonsepsi siswa pada materi kesetimbangan kelarutan. Rancangan penelitian eksperimen ini adalah randomized control group pretest-posttest. Instrumen yang digunakan adalah tes pilihan ganda tiga tingkat dengan menggunakan Certainty of Response Index. Populasi penelitian ini adalah siswa kelas XI salah satu sekolah negeri di kota Pekanbaru. Sampel penelitian ditentukan secara acak setelah dilakukan uji normalitas dan uji homogenitas. Kelas eksperimen diberi perlakuan dengan penerapan strategi pembelajaran POGIL sedangkan kelas kontrol tanpa penerapan strategi POGIL. Analisa data untuk pengujian hipotesis dilakukan menggunakan uji-t pihak kanan. Hasil penelitian memperlihatkan thitung < ttabel ( -0,59 < 2,02) dapat diartikan bahwa penerapan strategi POGIL dapat mereduksi miskonsepsi siswa pada materi kesetimbangan kelarutan dengan reduksi miskonsepsi sebesar 47,05 %.

Variation in Properties of Pre-Nucleation Calcium Carbonate Clusters Induced by Aggregation: A Molecular Dynamics Study

Numerous studies have speculated calcium carbonate (CaCO3) nucleation induced by pre-nucleation clusters (PNCs) aggregation. However, it is challenging for experiments to directly obtain the relationship between PNCs aggregation and nucleation. Herein, we employ molecular dynamics simulations to explore the variation during PNCs aggregation, which can describe the beginning stage of CaCO3 nucleation induced by PNCs aggregation in supersaturated solutions. The results reveal that the formation of CaCO3 nucleus consists of PNCs spontaneous growth, PNCs solubility equilibrium, and aggregation of PNCs inducing nucleation. The PNCs aggregation, accompanied by the variation in the configuration and stability of CaCO3 aggregate, breaks the solubility equilibrium of PNCs and creates conditions for the formation of the more stable nucleus. Besides, the CaCO3 nucleus with the higher coordination number and the lower hydration number form when decreasing the CaCO3 concentration or increasing the temperature. This work not only sheds light on the formation of the CaCO3 nucleus but also contributes to the explanation for CaCO3 polymorphism.

Insights of theoretical calculations and solubility equilibrium measurements into Ca2+-fluoride complexation and their dissociation behaviors in aqueous solutions: Implication for the association constant measured by fluoride ion selective electrodes

Although the Ca2+-F− association is of great importance for aqueous environments and industrial systems containing F−, as well as for defluorination processes, many details of the association solvation structures and...

Remediation of CO2 in Boudouard’s Reaction as an Example of Reversible Chemical Reaction

One of the fundamental elements of a scientist's work is the ability to lead observations of the phenomena that surround us and based on them making conclusions. These observations are conducted within the so-called scientific experiments. Lessons learned based on the results obtained in experiments allow researchers to better understand the essence of the phenomena occurring in the world around us. Drawing conclusions is not always easy. In order to achieve this skill, we must possess a well-established knowledge in the field of the phenomenon that interests us. The most striking example of how important skills are observation and drawing proper conclusions is the phenomenon of global climate warming. The main parameter influencing temperatures registered on Earth is the concentration of greenhouse gases in the atmosphere, and especially carbon dioxide created from combustion processes. A significant role in studies of the reduction of CO2 emissions plays chemists. To be sure that conducted by them experiments are optimally designed, it is necessary to ensure them with proper education already at the secondary school level. The main aim of this article was to conduct the study in order to explain chemical issues that create the greatest cognitive difficulties among students. The second aim of the article was to propose a chemical experiment to students that would allow them to find out more about the phenomena governing in the area of problematic issues. The proposed experiment is based on the concept of solubility equilibrium. Results of preliminary tests that have been carried out after applying this experiment on a small group of students, indicated their better understanding of the studied subject.

Improving Dissolution and Cytotoxicity by Forming Multidrug Crystals

Both rosiglitazone and metformin have effects on blood glucose regulation and the proliferation of liver cancer cells. Combination therapy with these two drugs is common and effective for the treatment of diabetes in the clinic, however, the application of these two drugs is influenced by the poor dissolution of rosiglitazone and the gastrointestinal side-effect of metformin resulting from a high solubility. The formation of a multidrug crystal form (Rsg-Met) by a solvent evaporation method can solve the solubility issue. Crystal structure data and intramolecular hydrogen bonds were detected by X-ray diffraction and infrared spectroscopy. Surprisingly, Rsg-Met shortens the time spent in solubility equilibrium and multiplies the dissolution rate of Rsg. Finally, we found that a low concentration of Rsg-Met enhanced the proliferation inhibition effect on liver cancer cells (HepG2, SK-hep1) compared with rosiglitazone, without affecting the human normal cell line LO2.

Misconception in Chemistry Education and Practices to Eliminate Them: Literature Analysis

Concepts can be examined in two groups as abstract and concrete ones. While concrete concepts are improved as a result of students’ experiences, it is considerably challenging for students to perceive abstract concepts. Since chemistry includes abstract concepts largely, it is considered to be hard to comprehend as a class by students. In fact, studies confirm this thought. On this particular issue, based on literature, it is clearly stated that students present themselves in learning environment, having some sort of thoughts and acknowledgments which are scientifically incorrect by a majority. The false information or acknowledgments are called misconception in the literature. Furthermore, it is also indicated that it is too hard to eliminate such misconceptions via the traditional teaching methods. Since each student constructs his/her own knowledge, understanding and concepts in accordance with his/her ability and experience, what matters here is, if prior knowledge of student involves any misconceptions, to identify and eliminate misconceptions. In this context, researches on identification and then elimination of misconceptions make a significant contribution to the chemistry education. In this paper, misconceptions determined and identified in literatures on subjects considered to be abstract, complex and hard to understand for students in the field of chemistry education are studied, namely solubility equilibrium, covalent bonds, ionic bonds, hydrogen bond and molecule geometry, activity concept in elements, chemical equilibrium, dissolution, electrolyse and battery; methods to remove those misconceptions are discussed; and in this study, the method of literature review, one of the qualitative research patterns, is used. To conclude, multiple misconceptions in chemistry education, specially related to abstract subjects were determined, and it is confirmed based on the literature that the methods developed in the framework of constructivist learning theory are used to remove such misconceptions.