• Journal of the Korean Chemical Society
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• v.44 no.5
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• pp.493-497
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• 2000

• Journal of the Korean Chemical Society
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• v.49 no.4
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• pp.355-362
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• 2005

• Journal of the Korean Chemical Society
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• v.51 no.5
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• pp.447-458
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• 2007

The purpose of this study was to explore high school teacher's and students' perceptions of learning difficulties of the ‘chemical bond' unit of the Chemistry II in the 7th national curriculum. The participants in this study were consisted of a teacher and his students(85) from the Chemistry II classrooms: they all answered to the questionnaire, and then some students and the teacher were interviewed individually. The results showed that there were big differences between the teacher's and his students' perceptions of 1) the most difficult unit for understanding; 2) concepts they learned; and 3) the most difficult concept for understanding in the classroom. Students thought that electro-negativity unit was the most difficult to understand while teacher thought molecular structure unit was the hardest unit to teach. And teacher taught all 32 subjects of chemical bond unit to students, but some students could not remember they learned all of them. Most difficult parts for students to understand were ‘Coulomb force' and ‘dipole moment', while the most difficult part for the teacher to teach was ‘the conceptual difference between atomic bond and intermolecular force'. The reasons caused the students' learning difficulties were analyzed and discussed based on the interview data, and then further study was presented.

• Journal of the Korean Chemical Society
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• v.62 no.4
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• pp.279-287
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• 2018

In this study, we analyzed the explanations and examples of Brønsted-Lowry model in Chemistry I and Chemistry II textbooks of the 2009 revised curriculum. In particular, the definition of the Brønsted-Lowry model, the examples, and the content of experiments were analyzed by the process perspective of chemical equilibrium, emergent process. The analyzed textbooks were 4 kinds of Chemistry I textbooks and 4 kinds of Chemistry II textbooks in 2009 revision curriculum. As a result, Chemical I textbooks did not adequately show the chemical equilibrium viewpoint when explaining the Brønsted-Lowry model. In the Chemistry II textbooks, the examples of Brønsted-Lowry model were not present emergent process viewpoint, and those were described as sequential viewpoint of Arrhenius model. In addition, examples of experiments to demonstrate the Brønsted-Lowry model of Chemistry II textbooks were insufficient. The experimental examples related to the definition of acid bases were at the level of classification by the color change of indicators. The experimental examples for explaining the strength of acid and base were to compare current intensity or amount of hydrogen gas generated from the reaction with metal. In addition, all textbooks presented the state of aqueous solution when describing the Brønsted-Lowry model, causing problems with differentiation from the Arrhenius model. Therefore, it is necessary to develop examples of experiments to help students understand Brønsted-Lowry model by presenting acid and base reaction in the non-aqueous solution state.

• Journal of the Korean Chemical Society
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• v.23 no.1
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• pp.1-6
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• 1979

The dipole moments for square planar and tetrahedral $[M(II)N_2S_2]$ type complexes are calculated, using the expansion method for spherical harmonics [M(II) = Co(II), Ni(II), Cu(II) or Zn(II)]. The calculated values of the dipole moments for these complexes are in the range of the experimental values. The possible structures for these complexes in benzene solution are discussed on the basis of the calculated dipole moments and the the magnetic properties.

• Journal of the Korean Chemical Society
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• v.42 no.4
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• pp.422-431
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• 1998

Tridentate Schiff base ligands such as $SIPH_2,\;SIPCH_2,\;HNIPH_2,\;and\; HNIPCH_2$ were prepared by the reaction of salicylaldehyde and 2-hydroxy-l-naphthaldehyde with 2-aminophenol and 2-amino-p-cresol. The structures and properties of ligands and their Co(II) complexes were investigated by elemental analysis, $^1H$NMR, IR, UV-visible spectra, and thermogravimetric analysis. The molar ratio of Schiff base to the metal of complexes was found to be 1:1. Co(II) complexes were contemplated to be hexa-coordinated octahedral configuration containing three water molecules. The redox process of ligands and complexes in DMSO solution containing 0.1 M TBAP as a supporting electrolyte were investigated by cyclic voltammetry with glassy carbon electrode. The redox process of the tridentate Schiff base ligands was totally irreversible. The redox process of Co(II) complexes were irreversible and one electron processes by two steps in diffusion controlled reaction. The reduction potential of the Co(II) complexes was shifted to the positive direction in the order [Co(Ⅱ)$(HNIPC)(H_2O)_3$]>[Co(Ⅱ)$(HNIP)(H_2O)_3$]>[Co(II)$(SIPC)(H_2O)_3$]>[Co(Ⅱ)$(SIP)(H_2O)_3], and their dependence on ligands were not so high.

• Journal of the Korean Chemical Society
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• v.54 no.3
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• pp.329-337
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• 2010

In this study, we analyzed the end-of-chapter questions in 8 types of chemistry II textbooks for science teachers according to revised Bloom's taxonomy of educational objectives not only to raise interests of questions in textbooks but also acquire a basic material for using questions in textbooks effectively. The results of classification following Bloom's cognitive category showed that 'Understanding(44.7%)' level was the most, then 'Application(29.9%)', Knowledge(15.6%) and 'Analysis (9.5%)' in order, which is distinct difference from the result of classification of the end-of-chapter questions in college general chemistry books which was 'Application', 'Analysis' and 'Understanding' in order. Especially, questions of 'Evaluation' level were not found at all in any textbook investigated and 'Synthesis(0.3%)' level was very few. On the other hand, the percentage of questions in 'Understanding' and 'Executing Quantitative' which required specific algorithms was 70% of total with most of the questions in 'Application' were 'Executing Quantitative'.

• Journal of the Korean Chemical Society
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• v.60 no.1
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• pp.59-68
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• 2016

The cultivation of scientific literacy in recent science education can be improved by experiencing and understanding scientific inquiry by which scientific knowledge is formed. The National Research Council(NRC) released the Next Generation Science Standards (NGSS) including 8 practices of science that help students experience scientists' inquiry and subdividing achievement standards to perform 8 practices of science into by grade clusters. This study was intended to examine science inquiry activities included in 4 high school chemistry II textbooks developed by the 2009 revised curriculum using the 8 scientific practices and their achievement standards for 9th-12th grade. The science inquiry activities and the science practices included in the 4 textbooks were 173 and 678. The science practices included in the inquiry activities of 4 textbooks included the most ‘analyzing and interpreting data.’ The ‘engaging in argument from evidence’, ‘Obtaining, Evaluating, and Communicating Information’ were less than other practices. The ‘asking questions and defining problem’ and ‘developing and using models’ were not nearly included in the 4 high school chemistry II textbooks.

• Journal of the Korean Chemical Society
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• v.67 no.1
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• pp.54-63
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• 2023

In this study, six types of 2015 revised curriculum ChemistryII textbooks were analyzed for conditions, definitions, whether or not critical points were displayed, and real-life examples of phase diagram. In this study, it was confirmed that the problems pointed out in several previous studies were not reflected in the 2015 revised curriculum ChemistryII textbook. The same as the situation defining the phase diagram, the translation of the phase diagram into a phase equilibrium diagram, the distinction between phase and state being unclear, the critical point not being shown in the phase diagram, real life examples are very limited what is being presented as is suggested as a problem. Therefore, it is necessary to reflect the results of various previous studies in the revised curriculum ChemistryII textbook that will be made in the future, specify the conditions under which the phase diagram is drawn, newly model the situation defining the phase diagram, and translate the phase diagram as a 'phase diagram'. It is necessary to use the term, clarify the distinction between phase and state, mark the critical point in the phase diagram, and develop various real-life examples.

• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.719-725
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• 1998

Tridentate Schiff base ligands were prepared by the reactions of salicylaldehyde and 2-hydroxy-1-naphthaldehyde with 2-aminophenol and 2-amino-p-cresol. And then Cu(II) complexes of those ligands were synthesized. The structures and properties of ligands and their complexes were studied by elemental analysis, $^1H$-NMR, IR, UV-visible spectra, and thermogravimetric analysis. The mole ratio of Schiff base to the metal of complexes was found to be 1:1. Cu(II) complexes were contemplated to be four-coordinated square planar configuration containing one water molecule. The redox process of ligands and complexes in DMSO solution containing 0.1 M TBAP as a supporting electrolyte was investigated by cyclic voltammetry and differential pulse voltammetry with glassy carbon electrode. The redox process of the tridentate Schiff base ligands was totally irreversible. The redox process of Cu(II) complexes was quasi-reversible and diffusion-controlled as one electron by one step process Cu(II)/Cu(I). The reduction potentials of the Cu(II) complexes shifted in the positive direction in the order of [Cu(II)(HNIPC)($H_2O$)]>[Cu(II)(HNIP)($H_2O$)]>[Cu(II)(SIP)($H_2O$)]>[Cu(II)(SIPC)($H_2O$)].