• Title/Summary/Keyword: Chemistry education

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Analysis of Chemistry Textbook Content and Teachers' Recognitions about Ionization and Ionization constant of Strong Acid (강산의 이온화도와 이온화 상수에 대한 화학 교과서 내용 및 교사들의 인식 분석)

  • Paik, Seoung-Hey;Go, Hyung-Suk;Jeon, Min-Cheol
    • Journal of the Korean Chemical Society
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    • v.57 no.2
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    • pp.279-288
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    • 2013
  • In this study, we analyzed the values of ionization and ionization constants in the chemistry textbooks developed during 1945-2009 year. The chemistry teachers compared strength of strong acids in aqueous solution by questionnaire. In the questionnaire, we searched chemistry teachers' cognitions about the discordance reason of ionization constant formulation and the values in the textbooks. The subjects were 46 chemistry teachers. As results, the teachers compared the strength of strong acids in aqueous solution based on the ionization and ionization constant values in the textbooks. They didn't notice the problem of discordance of ionization constant formulation and the values in the textbooks. Even though they recognized the problem, they could not find the solution, and thought the problem arrived by experiment error or measurement error.

The Study of Doxorubicin and its Complex with DNA by SERS and UV-resonance Raman Spectroscopy

  • Lee, Chul-Jae;Kang, Jae-Soo;Kim, Mak-Soon;Lee, Kwang-Pill;Lee, Mu-Sang
    • Bulletin of the Korean Chemical Society
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    • v.25 no.8
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    • pp.1211-1216
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    • 2004
  • The interaction of the antitumour agent doxorubicin with calf thymus DNA is investigated in an aqueous solution at a pH level of 6-7 with molar ratios of 1/10. A UV-resonance Raman spectroscopy and surface enhanced Raman spectroscopy are used to determine the doxorubicin binding sites and the structural variations of doxorubicin-DNA complexes in an aqueous solution. Doxorubicin intercalates with adenine and guanine via a hydrogen bond formation between the N7 positions of purine bases and the hydroxyl group of doxorubicin.

Singlet-Triplet Reactivity of 1-Methyl-2-Cyclohexenyl Aryl Ketones : Racemization vs 1,3-Acyl Shift in the Excited States

  • Woo Ki Chae;Mi Young Chae;Mi Kyung Park;Chung Hee Lee;Eun Hee You
    • Bulletin of the Korean Chemical Society
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    • v.11 no.3
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    • pp.241-244
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    • 1990
  • The photochemistry of 1-Methyl-2-cyclohexenyl aryl ketones (phenyl ketone 7a, p-toluyl ketone 7b, biphenyl ketone 7c and -naphthyl ketone 7d) is reported. The aryl ketone 7a, 7b and 7c undergo photo-racemization with efficiencies of 0.75, 0.79 and 0.76 respectively on direct irradiation. Direct irradiation of the ketone 7d, however, undergoes 1,3-shift with an efficiency of 0.02. Triplet states are responsible for the racemizations and singlet state is responsible for 1,3-shift as in general. The ketone 7a, 7b and 7c are good example of a few ${\beta},{\gamma}$-unsaturated ketones which undergo efficient intersystem crossing on direct irradiation.

An Investigation Into the Effects of AI-Based Chemistry I Class Using Classification Models (분류 모델을 활용한 AI 기반 화학 I 수업의 효과에 대한 연구)

  • Heesun Yang;Seonghyeok Ahn;Seung-Hyun Kim;Seong-Joo Kang
    • Journal of the Korean Chemical Society
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    • v.68 no.3
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    • pp.160-175
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    • 2024
  • The purpose of this study is to examine the effects of a Chemistry I class based on an artificial intelligence (AI) classification model. To achieve this, the research investigated the development and application of a class utilizing an AI classification model in Chemistry I classes conducted at D High School in Gyeongbuk during the first semester of 2023. After selecting the curriculum content and AI tools, and determining the curriculum-AI integration education model as well as AI hardware and software, we developed detailed activities for the program and applied them in actual classes. Following the implementation of the classes, it was confirmed that students' self-efficacy improved in three aspects: chemistry concept formation, AI value perception, and AI-based maker competency. Specifically, the chemistry classes based on text and image classification models had a positive impact on students' self-efficacy for chemistry concept formation, enhanced students' perception of AI value and interest, and contributed to improving students' AI and physical computing abilities. These results demonstrate the positive impact of the Chemistry I class based on an AI classification model on students, providing evidence of its utility in educational settings.

Stoichiometric Solvation Effects. Solvolysis of Trifluoromethanesulfonyl Chloride

  • Koo, In-Sun;Yang, Ki-Yull;Park, Jong-Kuen;Woo, Mi-Young;Cho, Jun-Mi;Lee, Jong-Pal;Lee, Ik-Choon
    • Bulletin of the Korean Chemical Society
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    • v.26 no.8
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    • pp.1241-1245
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    • 2005
  • Solvolyses of trifluoromethanesulfonyl chloride (TFMSC) in water and in aqueous binary mixtures of acetone, ethanol and methanol are investigated at 25, 35 and 45 ${^{\circ}C}$. The Grunwald-Winstein plot of first-order rate constants for the solvolytic reaction of TFMSC with YCl (based on 2-adamantyl chloride) shows marked dispersions into three separate curves for three aqueous mixtures. The extended Grunwald-Winstein plots for the solvolysis of TFMSC show better correlation. The large negative ${\Delta}S^{\neq}$ and relatively small positive ${\Delta}H^{\neq}$ reveals that the solvolytic reaction proceeds via a typical bimolecular reaction mechanism. The l and m values determined in various solvents are consistent with the proposed mechanism of the general base catalysis $S_AN/S_N2$reaction mechanism for TFMSC solvolyses based on mass law and stoichiometric solvation effect studies.