• Title/Summary/Keyword: xidation-reduction

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Problem Analysis and Improvement of an Experiment on Reactivityof Metals in ChemistryⅠ (화학Ⅰ 금속의 반응성 실험의 문제점 분석 및 개선방안)

  • Seong, Suk-kyoung;Choi, Chui-Im;Jeong, Dae-Hong
    • Journal of the Korean Chemical Society
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    • v.53 no.3
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    • pp.368-376
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    • 2009
  • In this study we investigated and tried to understand problems monitored in an experiment on reactivity of metals in chemistry I. Three problems were discussed. First, the reason that aluminium plate does not react with other metal ions such as zinc, iron and copper was studied and the way to overcome this problem was suggested. Second, the reason that the bubbles were generated when FeS$O_4$(aq) and Zn(s) react was discussed. Third, the precipitates which appeared in the reaction of FeS$O_4$(aq) and Zn(s) were identified. Through reference study and experimental investigation, we could reach the following results. First, aluminium could not react with other metal ions due to the surface oxide layer that is formed very fast and prevents aluminium from reacting with metal ions in solution. This problem could be overcome by allowing a competing reaction of acid and aluminium during the reaction of aluminium and metal ions. Second, the observed bubbles were identified to be hydrogen gas, produced by the reaction between metals and hydronium ion in the solution. Third, black precipitates that were produced on the surface of zinc plate and exhibited magnetic property were characterized to be $Fe_3O_4$(s), and brown precipitates that were produced in the solution phase were to be $Fe_2O_3$(s) by the analysis of X-ray photoelectron spectra.