scholarly journals MENTAL MODEL OF PROSPECTIVE CHEMISTRY TEACHER ON EQUILIBRIUM CONSTANT AND DEGREE OF DISSOCIATION

2019 ◽  
Vol 3 (2) ◽  
pp. 249-262
Author(s):  
Anggra Prasetya Cahya ◽  
Antuni Wiyarsi ◽  
Anti Kolonial Prodjosantoso
Keyword(s):  
Equilibrium Constant ◽  
Mental Model ◽  
Chemistry Teacher ◽  
Scientific Model ◽  
Reaction Conditions ◽  
Study Program ◽  
Chemistry Teachers ◽  
Degree Of Dissociation ◽  
Reaction Coefficient ◽  
Dissociation Degree

MODEL MENTAL CALON GURU KIMIA PADA KONSEP TETAPAN KESETIMBANGAN DAN DERAJAT DISOSIASIAbstrakPenelitian ini bertujuan untuk mengeksplorasi model mental calon guru kimia pada konsep tetapan kesetimbangan dan derajat disosiasi. Penelitian ini menggunakan jenis penelitian kualitatif eksploratif. Penelitian dilaksanakan pada mahasiswa semester lima di Program Studi Pendidikan Kimia Universitas Riau. Hasil penelitian menunjukkan bahwa model mental mahasiswa sebagai calon guru kimia pada konsep tetapan kesetimbangan terbagi menjadi enam model yang tergolong mengalami miskonsepsi yaitu kekurangpahaman mengenai kesetimbangan heterogen, kesalahan penulisan persamaan Kp, pemahaman tentang nilai Kc bergantung pada pangkat dari koefisien reaksi pada kondisi reaksi yang sama, kesalahan menentukan satuan tetapan kesetimbangan, kesalahan menghitung Δn, dan tidak mengetahui koefisien reaksi zat yang tidak tertulis angka. Adapun model mental calon guru kimia pada konsep derajat disosiasi terbagi menjadi tiga yaitu model saintifik derajat disosiasi, model tanpa pengertian disosiasi, dan model kesalahan jumlah mol awal. Kata kunci: model mental, calon guru kimia, tetapan kesetimbangan, derajat disosiasiAbstractThis study was aimed at exploring the mental model of prospective chemistry teacher on the concepts of equilibrium constant and the degree of dissociation. This study used explorative qualitative research model. The research was conducted at the fifth semester students in the Chemistry Study Program at Riau University. The results show that the mental model of students as prospective chemistry teachers on the concept of the equilibrium constant is divided into six models that are classified as experiencing misconceptions: the lack of understanding about heterogeneous equilibrium, error writing in Kp equation, misunderstanding of the value of Kc depends on the rank of the reaction coefficient under the same reaction conditions, the error of determining the unit of equilibrium constant, the error of calculating Δn, and the lack of understanding regarding to the reaction coefficient of an unwritten number of substances. The mental model of prospective chemistry teachers on the concept of dissociation degree is divided into three: the scientific model of dissociation degree, the model without understanding dissociation, and the initial mole number error model.

scholarly journals ANALISIS MISKONSEPSI ASAM BASA CALON GURU KIMIA DENGAN METODE THREE-TIER TEST

2020 ◽  
Vol 8 (1) ◽  
pp. 10
Author(s):  
Abdullah Abdullah
Keyword(s):  
Teacher Candidates ◽  
Sampling Technique ◽  
Chemistry Teacher ◽  
Acid Base ◽  
Study Program ◽  
Dissociation Degree ◽  
Acid And Base ◽  
Study Population ◽  
The University ◽  
Mathematical Operations

This study aims to identify the misconceptions of a prospective chemistry teacher. The study population was all students of the Chemistry Study Program at the University of Riau, while the sample was 66 students at the Chemistry Study Program at the University of Riau, selected by cluster random sampling technique. Conception data of chemistry teacher candidates on acid-base subjects have been identified and obtained by providing valid acid-base TTT diagnostic tests to chemistry teachers candidates. The result of this research showed that chemistry teacher candidate who experienced misconception on acid-base subject were 66.5% from 4 main concepts studied, namely acid and base concepts (51.15%), pH and pOH concepts and their calculations (79.06%), the concept of acid-base dissociation degree (75.43%), and the concept of acid-base titration and indicator (58.13%). The study also revealed that some students have difficulties in performing mathematical operations using logarithms.

scholarly journals Why school-related content knowledge for pre-service chemistry teachers should include basic concepts in organic chemistry

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jolanda Hermanns ◽  
Nico Ermler
Keyword(s):  
Organic Chemistry ◽  
Mixed Methods ◽  
Content Knowledge ◽  
Structure And Function ◽  
Mixed Methods Study ◽  
Chemistry Teacher ◽  
Chemistry Teachers ◽  
Basic Concepts ◽  
The Moment ◽  
And Function

Abstract In this paper we describe and evaluate a study on the use of concepts in organic chemistry while solving tasks that are designed after the concept of school-related content knowledge (SRCK). The study was designed as a mixed methods study and conducted at a German university for the content of “organic chemistry”. As the results of this study show, the students rate the tasks and the use of anchoring concepts as for example “bonds” or “structure and function” as relevant for their future profession as a chemistry teacher. They therefore propose that concepts should be an integral part of their university studies as they find it lacking at the moment. Concepts can also be seen as an opportunity to build a bridge between school knowledge and university knowledge.

scholarly journals Impact of Solvation on the Structure and Reactivity of the Co3O4 (001)/H2O Interface: Insights From Molecular Dynamics Simulations

2020 ◽  
Vol 8 ◽  
Author(s):  
T. Kox ◽  
E. Spohr ◽  
S. Kenmoe
Keyword(s):  
Molecular Dynamics ◽  
Contact Layer ◽  
Ab Initio Molecular Dynamics ◽  
Water Dissociation ◽  
Degree Of Dissociation ◽  
Water Films ◽  
Dissociation Degree ◽  
In Operando ◽  
Dynamics Simulations ◽  
Potential Use

The spinel Co3O4 has many beneficial properties for potential use in catalysis. In operando, water is always present and alters the properties of the catalyst. We have used ab initio molecular dynamics to understand the effect of water and solvation on the structure and reactivity of the Co3O4 (001) A-type and B-type surface terminations. Water adsorbs on both terminations via a partial dissociative mode, and the A-termination is seen to be more reactive. On this surface, a higher degree of dissociation is observed in the topmost layers of the crystal in contact with water. Water dissociates more frequently on the Co2+ sites (about 75%) than on the adjacent Co3+ sites, where the degree of dissociation is about 50%. Increasing water coverage does not change the degree of water dissociation significantly. OH− adsorption on the Co2+ sites leads to a reduction of the amount of reconstruction and relaxation of the surface relative to the clean surface at room temperature. Proton transfer within the water films and between water molecules and surface has localized character. The B-terminated interface is less dynamic, and water forms epitactic layers on top of the Co3+ sites, with a dissociation degree of about 25% in the contact layer.

scholarly journals ANALISIS DESKRIPTIF BERBASIS MODEL MENTAL FISIKA TERHADAP PEMAHAMAN KOGNITIF MAHASISWA PADA KONSEP KINEMATIKA PARTIKEL DAN GERAK PARABOLA

2020 ◽  
Vol 3 (3) ◽  
pp. 255-260
Author(s):  
Nyoman Rohadi ◽  
Iwan Setiawan
Keyword(s):  
Physics Education ◽  
Mental Model ◽  
Uniform Motion ◽  
Study Program ◽  
First Semester ◽  
Education Study ◽  
The Mean ◽  
Motion Problems ◽  
Physics Problems

ABSTRAK Artikel ini menguraikan hasil analisis deskriptif berbasis model mental fisika terhadap pemahaman kognitif mahasiswa semester pertama tahun ajaran 2019/2020 prodi pendidikan fisika JPMIPA FKIP UNIB Universitas Bengkulu pada konsep kinematika partikel dan gerak parabola. Data yang dianalisis diperoleh dari hasil pretest, lembar kerja mahasiswa (LKM),  dan data hasil posttest dari mahasiswa yang berjumlah 28 orang mengikuti kuliah fisika dasar 1. Skor rata-rata data hasil Pretest adalah  44,64 pada rentang nilai yang cukup lebar yaitu 30-80. Skor rata-rata pada data hasil Posttest adalah 71,42 dengan rentang 50-100. Skor rata-rata pada posttest mengalami peningkatan  sebesar 26,78 atau 60% terhadap skor rerata Pretest. Hasil analisis deskriptif pada data hasil pretest dan LKM menunjukkan  rendahnya penguasaan mahasiswa dalam memahami soal-soal bentuk diagram gambar fisika dan grafik fisika. Tetapi mahasiswa tidak mengalami kesulitan dalam menerapkan rumus-rumus untuk  menjawab soal-soal konsep GLB. meskipun ada sejumlah mahasiswa salah menentukan besarnya percepatan pada soal GLBB. Dari analisis pada posttest menunjukkan adanya peningkatan kompetensi kognitif pada mahasiswa.  Mahasiswa telah mampu menerapkan model mental fisika dalam memahami dan memecahkan soal-soal berbentuk konseptual, diagram, grafik, dan penerapan rumus fisika  pada materi kinematika partikel, dan konsep gerak parabola.  Kata kunci: model mental, kompetensi kognitif, kinematika partikel dan gerak parabola ABSTRACT This article portrays a deskriptif analysis results based on physics mental model toward cognitif reasoning of the first semester in the year of study 2019/2020 students in physics education study program of  the JPMIPA FKIP Bengkulu University on the concepts of kinematics particle and parabolic motion. The analized data were a pretestt, students work sheets (SWS) and posttest data Of 28 students who participated in basics physics 1 class. The mean score of the pretestt data was 44,64 in a range score  of 30.00-80.00. The mean score of the posttest data was 71,42 in a range score of 50.00-100.00. The mean score of posttest increased about 60% compare with the mean score of pretestt.  The deskriptif analysis on the pretestt data and the SWS data indicated that a low kognitif competency among the students in understanding physics diagram and solving physics graphs related problems. But no student faund any dificulty in using physics equations on solving the uniform motion problems. Eventhough some students failed in solving the amount of  acceleration related problems. The analysed results of the posttest data indicated an improvement on students kognitif competency. Most of the students could apply the physics mental model on solving the conceptual, diagram, graph, and matematics related physics problems. Keywords: mental model, kognitif competency, arithmatics particle, and parabolics motion.

INFLUENCE OF SELF-ANALYSIS AND REFLEXIVE PERSCRUTATION OF PRIE-SERVICE TEACHERS THROUGH VIDEO RECORDING IN CHEMISTRY TEACHERS EDUCATION

2010 ◽  
Vol 7 (1) ◽  
pp. 8-14
Author(s):  
Vitor Zanni ◽  
Agnaldo Arroio
Keyword(s):  
Professional Development ◽  
Discourse Analysis ◽  
Key Words ◽  
Video Analysis ◽  
Video Recording ◽  
Chemistry Teacher ◽  
Chemistry Teaching ◽  
Pedagogical Strategies ◽  
Chemistry Teachers ◽  
Methodological Tool

In this work, we present an approach on methodology of teaching where pre-service chemistry teachers are required to analyze sequences of digital video of chemistry teaching in real classrooms. We utilize discourse analysis to help pre-service chemistry teachers to reflect on their pedagogical strategies and discursive interactions. The results showed that the integration of video analysis on the pre-service chemistry teacher training is an important methodological tool on professional development of chemistry teachers. Key-words: pre-service education, video, chemistry teacher, ICT.

Chemistry critical friendships: investigating chemistry-specific discourse within a domain-general discussion of best practices for inquiry assessments

2020 ◽  
Vol 21 (1) ◽  
pp. 452-468 ◽  
Author(s):  
Adam G. L. Schafer ◽  
Ellen J. Yezierski
Keyword(s):  
High School ◽  
Best Practices ◽  
Assessment Practices ◽  
Chemistry Teacher ◽  
High School Chemistry ◽  
Teacher Discourse ◽  
Chemistry Teachers ◽  
Use Of Data ◽  
Teacher Professional ◽  
Assessment Beliefs

High school chemistry teachers struggle to use assessment results to inform instruction. In the absence of expert assistance, teachers often look to their peers for guidance and support; however, little is known about the assessment beliefs and practices of high school chemistry teachers or the discourse mechanisms used as teachers support one another. Presented in this paper are the results from analyzing a discussion between five high school chemistry teachers as they generated a set of best practices for inquiry assessments. To analyze the discussion, a novel representation called a discourse map was generated to align the analyses conducted on chemistry teacher discourse as they temporally occurred. Results show the utility of the discourse map for evidencing critical friendship and assessment practices evoked by the teachers during the discussion of best practices. Implications for the structural considerations of materials and chemistry teacher professional development are presented as well as potential future investigations of teacher discourse regarding the use of data to inform instruction.

Investigating high school chemistry teachers’ assessment item generation processes for a solubility lab

2021 ◽  
Author(s):  
Adam G. L. Schafer ◽  
Ellen J. Yezierski
Keyword(s):  
High School ◽  
Knowledge Bases ◽  
Chemistry Teacher ◽  
High School Chemistry ◽  
Item Generation ◽  
Chemistry Teachers ◽  
Pedagogical Content ◽  
Assessment Item ◽  
Teacher Professional ◽  
Guidelines And Standards

Designing high school chemistry assessments is a complex and difficult task. Although prior studies about assessment have offered teachers guidelines and standards as support to generate quality assessment items, little is known about how teachers engage these supports or enact their own beliefs into practice while developing assessments. Presented in this paper are the results from analyzing discourse among five high school chemistry teachers during an assessment item generation activity, including assessment items produced throughout the activity. Results include a detailed description of the role of knowledge bases embedded within high school chemistry teachers’ pedagogical content knowledge and the processes used to enact these knowledge bases during planned formative assessment design. Implications for chemistry teacher professional development are posited in light of the findings as well as potential future investigations of high school chemistry teacher generation of assessment items.

scholarly journals Mainstreaming multiple uses of chemicals in chemistry teacher education programs of Africa

2017 ◽  
Vol 89 (2) ◽  
pp. 205-209
Author(s):  
Temechegn Engida
Keyword(s):  
Teacher Education ◽  
Teacher Education Programs ◽  
Chemistry Teacher ◽  
Education Programs ◽  
Chemistry Teachers ◽  
Multiple Uses ◽  
Multiplier Effects

Abstract:Many compounds can be used for or manipulated to serve a variety of purposes. Chemistry teachers and the chemistry curricula they use, however, do not directly deal with the idea of the use, misuse, and abuse of multi-use chemicals. This paper therefore attempts to explore strategies in mainstreaming the concepts of multi-use chemicals in Chemistry teacher education programs. It is believed that teacher education programs have multiplier effects since they are intended to cover both pre- and in-service chemistry teachers.

Sign in / Sign up

Export Citation Format

Share Document