Solubility and Complex-Ion Equilibria

Solubility and Complex-Ion Equilibria broadens the previous chapter’s coverage of equilibria to include aqueous systems containing two or more solutes of slightly soluble ionic compounds and the formation of metal complexes in solution. Solubility equilibria which allow quantitative predictions of how much of a compound will dissolve under given conditions are covered. The meaning of the solubility product constant (K sp) and how to calculate it from molar solubility values is presented. Also discussed is determination of molar solubility from K sp. Calculations demonstrate how to predict the formation of a precipitate by comparing the ion product or solubility quotient (Q) with K sp. Formation constants of complex ions and calculations involving complex ion equilibria are explained.

The Development Higher Order Thinking Skill (Hots) As Questions In Chemistry Study (Solubility And Solubility Product Constant)

The significance of critical thinking as one of the 21st century skills makes the Indonesian Ministry of Education and Culture integrate Higher Order Thinking Skill (HOTS) in the latest national curriculum. Students critical thinking skills to working on HOTS assessment are fundamental, especially in learning chemistry lessons. The research purpose is to analyze the quality of HOTS chemistry questions/ assessment and to observe the teachers and students responses to computer-based test instruments developed using Wondershare Quiz Maker Software (WQM). The research method used Research And Development (R & D) Borg & Gall model. The sample was determined by Random Sampling Technique in total 104 students from several high school in Banda Aceh, it is SMAN 4, SMAN 5, SMAN 8 and SMAN 11. The data analysis technique was through calculating the percentage score of the assessment quality and analyzing the question items quantitatively such as validity, reliability, difficulty level of the questions, differential question power tests and distracting question power using proanaltes. The results showed that the quality of HOTS in chemical questions tested (for the solubility subject and the solubility product constant in terms of qualitative analysis of the items) in the validation test gained average score, it is 98.1%, means the items are qualified categories. In terms of quantitative analysis question items, it reached 95% valid and 5% invalid and the reliability test score was 0.740, are in high category. The questions difficulty covers 95% medium and 5% are in difficult level. The questions differential power for each category is 65% good, 30% medium and 5% less. The teachers and students response to the development of the computer-based HOTS test instrument using WQM software was positive and show good result. The teacher response positively on score strongly agreed was 83.3% and agreed 16.7%, while the students response on score strongly agreed was 27.2% and 63.3% agreed. The research conclusion there is significant students critical thinking skills improved (in learning the solubility and the solubility product constant chapter) by using HOTS assessment using Wondershare Quiz Maker software.

Solubility product constant directs the formation of biomolecular condensates

Biomolecular condensates, formed by liquid-liquid phase separation (LLPS), are important cellular structures. Using stochastic network-free kinetic models, we establish a physical-chemical basis for the concentration threshold of heterotypic multivalent molecules required for LLPS. We associate phase separation with a bimodal partitioning of the cluster distribution into small oligomers vs. huge polymers. The simulations reveal that LLPS obeys the solubility product constant (Ksp): the product of monomer concentrations, accounting for ideal stoichiometries, does not exceed a threshold no matter how much additional monomer is added to the system – additional monomer is funneled into large clusters. The Ksp applies over a range of valencies and stoichiometries. However, consistent with the importance of disordered domains for LLPS, removing flexible linker domains funnels valency-matched monomers into a “dimer trap”, and Ksp no longer defines a threshold for large cluster formation. We propose Ksp as a new tool for elucidating biomolecular condensate biophysics.

STUDI KORELASI EFIKASI DIRI DENGAN HASIL BELAJAR MAT¬ERI KELARUTAN DAN HASIL KALI KELARUTAN

Correlation study between self efficacy and learning outcome of solubility and solubility product constant material at XI MIA 1 Students of MAN 1 Banjarmasin at 2016/2017 Academic Year was conducted. This research aims to determine the correlation between self efficacy and learning outcome of solubility and solubility product constant material. This research applies quantitative method, that is descriptive correlational study with one shot case study as the research design. Research sample is XI MIA 2 Class with total 37 students. Test technique and questionnaire is used for data collection. Data analysis technique uses Pearson correlation test and descriptive analysis. Pearson correlation test is used to know correlation between self efficacy and learning outcome. The research’s result shows that there is a positive and significant correlation between self-efficacy and students’ learning outcome. The value of Pearson Correlation is 0,674 which shows that correlation between that two variables is a strong correlation. Keywords: correlation, self efficacy, learning outcome. Abstrak. Telah dilakukan penelitian tentang studi korelasi efikasi diri dengan hasil belajar materi kelarutan dan hasil kali kelarutan siswa kelas XI MIA MAN 1 Banjarmasin tahun pelajaran 2016/2017. Tujuan dari penelitian ini adalah mengetahui adanya hubungan efikasi diri dengan hasil belajar siswa pada materi kelarutan dan hasil kali kelarutan. Penelitian ini menerapkan metode kuantitatif berupa studi deskriptif korelasional dengan desain penelitian one shot case study. Penelitian dilakukan terhadap sampel sebanyak 37 orang dari kelas XI MIA 2. Data dikumpulkan melalui teknik tes dan kuesioner. Data dianalisis dengan uji korelasi Pearson dan analisis deskriptif. Untuk mengetahui hubungan antara efikasi diri dengan hasil belajar digunakan uji korelasi Pearson. Hasil penelitian menunjukkan bahwa terdapat hubungan yang positif dan signifikan antara efikasi diri dengan hasil belajar siswa. Nilai Pearson Correlation pada SPSS sebesar 0,674 menunjukkan bahwa kedua variabel tersebut berhubungan kuat. Kata kunci: korelasi, efikasi diri, hasil belajar

ANALISIS FAKTOR-FAKTOR PENYEBAB KESULITAN BELAJAR SISWA PADA MATERI KELARUTAN DAN HASIL KALI KELARUTAN

AbstrakPenelitian ini bertujuan mendeskripsikan faktor-faktor penyebab kesulitan belajar siswa SMA Negeri 2 Banjar dalam mempelajari materi kelarutan dan hasil kali kelarutan. Subjek penelitian ini adalah 85 orang siswa dari seluruh kelas XII MIPA. Jenis penelitian yang digunakan adalah penelitian kualitatif. Pengambilan data dilakukan dengan cara tes dan wawancara. Data yang diperoleh berupa informasi mengenai faktor-faktor penyebab kesulitan belajar siswa pada materi kelarutan dan hasil kali kelarutan. Hasil penelitian ini menunjukkan bahwa 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 pendukung materi kelarutan dan hasil kali kelarutan rendah, dan kemampuan siswa dalam aspek perhitungan lemah. Faktor eksternal, meliputi penyesuaian kemampuan siswa dalam penerapan metode mengajar guru dalam kelas kurang, cara guru mengelola pembelajaran kimia, pengaruh teman sebaya, dan waktu pembelajaran kimia yang kurang efektif.Kata Kunci: faktor kesulitan belajar, kelarutan dan hasil kali kelarutan Abstract This study aimed to describe the cause factors of students'learning difficulties at the SMA Negeri 2 Banjar in learning solubility and solubility product constant. The subjects were 85 students from all class XI MIA. The type of research was qualitative research. The data were collected by using test and interview. The data were the information about the cause factors of students’ learning difficulties insolubility and solubility product constant. The result of this research showed internal factors that caused students'difficultiesof learning, namely less learning interest toward chemistry, less learning motivation toward chemistry, less meaning toward solubility and solubility product constant concepts, less understanding toward concepts supporting solubility and solubility product constant topic, less calculation ability. The external factor was less adjustment of students' capability into teacher’s teaching method used in classroom, the way teacher’s managed chemistry learning, friends influence, and less effective learning time. Key words: factors of difficulties of learning, solubility and solubility product constant

From inorganic precipitation to organic aggregation: solubility product constant-mediated specific metal-ion lighting-up using a triazolium iodide organic fluorescence tag

Innovation in sensing strategies is a continual goal pursued by analytical chemists.