The contamination of wastewater with metals and the use of biotechnologies to remove them is commonly discussed in theoretical biology, microbiology and biotechnology classes aimed at undergraduate students. This work introduces an easy, economical and safe practical laboratory class related to this topic. The practice consists in performing batch…

This study aimed at determining the category and analyzes the mental models of the students from three senior high school clusters (low, medium, high) on the solubility and solubility product topic, knowing students' opinions on chemistry subject, knowing learning methods and assessment that teacher used in solubility and solubility products…

The application of the Study and Research Path (SRP) methodology for learning general chemistry, a fundamental course often found in the first-year curriculum of many technical degrees, is investigated. In recent years, SRPs have emerged as interesting inquiry and project-based teaching formats. In an SRP, the search for an answer to a generating…

"E"-pH (Pourbaix) diagrams provide an important graphical link between the thermodynamic calculations of potential, pH, equilibrium constant, concentration, and changes in Gibbs energy and the experimentally observed behavior of species in aqueous solutions. The utility of "E"-pH diagrams is extended with the introduction of an additional…

Although children develop categorical speech perception at a very young age, the maturation process remains unclear. A cross-sectional study in Mandarin-speaking 4-, 6-, and 10-year-old children, 14-year-old adolescents, and adults (n = 104, 56 males, all Asians from mainland China) was conducted to investigate the development of categorical…

This research investigated translation strategies used in translating English relative clauses with the relativizers 'who,' 'which,' and 'that' into Thai. The data comprised 348 sentence pairs from two English novels and their Thai translations. It was hypothesized that the adopted translation strategies could be divided into two groups: literal…

The formation and the hydrolysis of organic salts produced by the titration of a 0.1 M solution of the following amines: methyl-, dimethyl-, trimethyl-, ethyl-, diethyl-, and triethylamine with a 0.1 M solution of acetic, chloroacetic, and dichloracetic acids are studied. The pK[subscript b] of the amine and the pH at the end point were determined…

This work describes an effective, low cost method to anodize small aluminum objects. The use of a PVC spacer between the anode and cathode significantly reduces the size of the electrochemical cell and electrolyte required for its operation. Students will explore the physical and chemical properties of aluminum and anodized aluminum. They will…

3-D topographic surfaces ("topos") can be generated to visualize how pH behaves during titration and dilution procedures. The surfaces are constructed by plotting computed pH values above a composition grid with volume of base added in one direction and overall system dilution on the other. What emerge are surface features that…

This study introduces a small-scale chemistry practicum technique with the concept of acid-base identification, determination of pH with indicators, and neutralization reactions with the concept of titration. The first experiences of teachers and students in small-scale chemistry practicums are revealed. Action research was carried out to…

Identification of novel fermenting yeast is beneficial to the brewing industry to develop innovations in flavor or processes. In addition, there is a growing interest in sour beers, which are traditionally produced with bacteria such as Lactobacillus and Pediococcus. Here, we characterize a novel yeast, lab strain 'GY7B', and its ability to…

Through a descriptive exploratory research design, the current study purposed to diagnose students' misconceptions of acid-base concepts. A Three-Tier Diagnostic Test (TTDT) with 20 items was administered to 72 Thai and 64 Indonesian grade 12 students in the science program. The semi-structured interview was used to probe their responses to the…

Much of analytical chemistry involves the analysis of complex mixtures, where careful attention to sample preparation and method selectivity is required to avoid interferents and obtain accurate data. As this type of analysis is very different from simple colorimetric analysis that most students are exposed to in general chemistry, this laboratory…

The purpose of this study was to prove the mechanism of mineralization, when hydroxyapatite (HAP) is formed in blood plasma. These observations were substantiated by in vitro simulation of HAP crystallization in the plasma of healthy adults in a controllable quasi-physiological environment (T = 37°C, pH = 7.4) and at concentrations of dissolved Ca…

Four experiments examined the locus of impact of causal knowledge on consideration of alternative hypotheses in judgments under uncertainty. Two possible loci were examined; overcoming neglect of the alternative when developing a representation of a judgment problem and improving utilization of statistics associated with the alternative…