AbstrakPenelitian ini bertujuan mendeskripsikan dan menjelaskan kesulitan belajar siswa dan faktor-faktor penyebab kesulitan belajar siswa dalam mempelajari materi kelarutan dan hasil kali kelarutan. Subjek penelitian adalah 38 orang siswa dari seluruh kelas XII IPA. Metode penelitian yang digunakan adalah mixed method. Pengambilan data dilakukan dengan cara observasi, tes, dan wawancara. Analisis data yang dilakukan adalah analisis hasil observasi, analisis hasil tes diagnostik dan analisis hasil wawancara. Data yang diperoleh berupa hasil belajar siswa dan informasi mengenai faktor-faktor penyebab kesulitan belajar siswa pada materi kelarutan dan hasil kali kelarutan. Hasil penelitian menunjukkan bahwa bentuk kesulitan belajar siswa pada materi kelarutan dan hasil kali kelarutan adalah pemahaman materi prasayarat, menuliskan ionisasi garam, penggunaan rumus Ksp, pemahaman siswa pada konsep asam basa, pemahaman siswa pada konsep kesetimbangan kimia, pemahaman siswa pada penulisan persamaan reaksi, dan kemampuan operasi matematika. Faktor-faktor penyebab kesulitan belajar siswa yang disebabkan oleh faktor internal, meliputi: minat belajar kimia rendah, motivasi belajar kimia rendah, pemaknaan konsep siswa terhadap materi kelarutan dan hasil kali kelarutan rendah, pemahaman konsep prasyarat materi kelarutan dan hasil kali kelarutan rendah, dan kemampuan siswa dalam operasi matematika yang lemah. Faktor eksternal, meliputi: pengaruh negatif dari teman sebaya dan cara mengajar guru.Kata Kunci: kesulitan belajar, kelarutan dan hasil kali kelarutanAbstractThis study aims to describe and explain student learning difficulties and the factors that cause students' learning difficulties in learning the material solubility and solubility results. The research subjects were 38 students from all XII IPA classes. The research method used is a mixed method. Data retrieval is done by observation, tests, and interviews. Data analysis was carried out by analyzing the results of observations, analyzing the results of diagnostic tests and analyzing the results of interviews. Data obtained in the form of student learning outcomes and information about the factors that cause student learning difficulties in the material solubility and solubility results. The results showed that the form of student learning difficulties in the solubility and solubility results material was understanding pre-set material, writing salt ionization, using Ksp formula, understanding students on the concept of acid base, understanding students in the concept of chemical equilibrium, understanding students in writing equation, and mathematical operating abilities. Factors that cause student learning difficulties caused by internal factors include: low chemistry learning interest, low chemistry learning motivation, meaning of students' concept of solubility and low solubility products, understanding the concept of solubility material and low solubility results, and ability students in weak mathematical operations. External factors include: negative influence from peers and how to teach teachers.Keywords: learning difficulties, solubility and solubility results

Penelitian ini bertujuan untuk: (1) menentukan distribusi model mental mahasiswa calon guru kimia dalam memahami bahan kajian Stereokimia, serta (2) mengidentifikasi dan mendeskripsikan miskonsepsi khusus (specific misconceptions) dan model mental alternatif yang dimiliki oleh mahasiswa calon guru kimia.  Subyek penelitian adalah mahasiswa Jurusan Pendidikan Kimia FMIPA UNDIKSHA yang sedang mengambil mata kuliah Kimia Organik III di Kelas C Semeter V pada tahun ajaran 2013/2014.  Jumlah subyek penelitian sebanyak 28 orang.  Data dikumpulkan melalui instrumen tes hasil belajar berbentuk pilihan ganda dua tingkat, terdiri dari bagian isi dan bagian alasan.  Analisis data dilakukan secara deskriptif.  Hasil penelitian menunjukkan, (1) model mental mahasiswa calon guru kimia dalam memahami bahan kajian Stereokimia adalah: tidak ada konsep (20,71%), miskonsepsi spesifik (33,04%), model mental alternatif (12,50%), dan benar secara ilmiah (33,75%); serta (2) miskonsepsi tertinggi (92,86%) terjadi pada penentuan konfigurasi (R/S) senyawa berdasarkan proyeksi Newman, dan model mental alternatif tertinggi (32,14%) pada penggambaran proyeksi Fischer stereoisomer yang diketahui konfigurasi absolutnya.

This student self-assessment of chemistry laboratory basic skill performances is intended to overcome the heavy time-consuming and very intensive involvement of lecturer as the only performance assessor, promote and accelerate the skill improvement based on learner self-performance assessment. The study involved 26 students undertaking Basic Chemistry subject at Chemistry Education Department of Universitas Pendidikan Ganesha in Bali. The self-assessment applied the scoring rubric developed by Sudria and Sya’ban. Each item of the 22 assessment items applies five-scaled grading performance indicators as very good, good, sufficient, poor, and very poor. Every skill item was assessed at least three time along the semester and analyzed twice namely at the middle of the semester as data S1 and near the end of the semester as data S2. The same performance assessment was also conducted by a lecturer team as the laboratory work examination at the end of the course as reference data of S3. This study showed significant correlation of S1 and S2 toward S3 with score correlation amounts of 0.520 for r1-3 and 0.588 for r2-3 which were above the critical value of 0.374 at 95% confidence. Guidance and monitoring during laboratory work supported to the success of the self-assessment study.

First year students of the Chemistry Education Study Program have some problems in practicum because the students' basic laboratory skills are low. The current practicum guide is not sufficient to provide information on basic skills for working in the laboratory. This condition causes students to have problems practicum and there is a potential risk of accidents. This study aims to produce a handbook for Basic Chemistry I with Occupational Health and Safety (K3) which is feasible to be implemented in Basic Chemistry Practicum I. This research was a Research and Development (R&D) with a 4-D development model, consist of 4 main stages, Define, Design, Develop and Disseminate. The research was limited to the development stage, which ended in the legibility test. Based on expert assessment the results showed that the handbook for Basic Chemistry Practicum I with K3 was very valid in terms of content (3.75), language (3.70), and media (3.6) from a maximum score of 4. The results of the readability test from 9 students showed that all students gave clear assessments. They understood the contents and guidelines for practicum on Basic Chemistry 1 with K3 very well. The conclusion of this study is Basic Chemistry Practicum I Handbook with K3 content is valid to be implemented from the aspects of content, presentation, language, media, and readability.

This study aims to describe the profiles of students’ mental models of SMA Negeri 1 Singaraja on the topic of acid-base. The study was a survey research. The population consisted of 279 people of the eleventh-grade students of Mathematics and Natural Sciences Classes of SMA Negeri 1 Singaraja in Buleleng Bali Indonesia in a school year of 2018/2019. In this study, all members of the population became members of the samples. The data needed in this study were the student’s mental model scores. Data were collected by a diagnostic test. Data were analyzed descriptively by grouping students’ mental models into three types, including scientific, synthetic, and initial mental models. The results showed that students had scientific, synthetic, and initial mental models of 2.69%, 61.766%, and 35.56% respectively.