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Titrimetric Analysis
Published in Pradyot Patnaik, Handbook of Environmental Analysis, 2017
An oxidation–reduction titration or redox titration is an oxidation–reduction reaction involving a transfer of electron(s) between two substances in solution. A substance is said to be oxidized when it loses electron(s) and reduced when it gains electron(s). Examples of oxidation–reduction reactions are illustrated below: Ce4++Fe2+⇔Ce3++Fe3+H3AsO3+2Ce4++H2O⇔H3AsO4+2Ce3++2H+
Effects of Nb and Sn co-doping on the structure and properties of SrCoO3-δ oxygen transport membranes
Published in Journal of Asian Ceramic Societies, 2020
Jong Hyun Park, Young A. Lee, Ji Haeng Yu, June Hyuk Lee, Hana Yoon, Younghyun Cho, Chung-Yul Yoo
The chemical nature of SCN, SCNT3, and SCNT5 was examined by XPS (Thermo VG Scientific K-alpha) and the obtained spectra were analyzed using the Fityk program [40], where the spectral background was removed using the Shirley function. All peaks were adjusted to a binding energy of 285 eV for the aliphatic carbon. The absolute oxygen stoichiometry value at 25°C was also characterized by redox titration. For the titration, approximately 0.1 g of the powder was dissolved in 1 M HCl (Sigma Aldrich, 37%) and 2 M KI (Sigma Aldrich, ≥ 99%) was added. This solution was titrated against a 0.01 M Na2S2O3 solution (Sigma Aldrich, ≥ 99.99%) using starch indicator under flowing nitrogen gas [41]. The titration was repeated three times and averaged to estimate the oxygen stoichiometries of SCN, SCNT3, and SCNT5. The changes in the oxygen stoichiometries of SCN, SCNT3, and SCNT5 were determined by thermogravimetry (SDT 2960, TA Instruments) in the temperature range from 25°C to 950°C. a heating rate of 2°C·min−1 was employed in dry air with a flow rate of 100 mL∙min−1.
Redox potential measurement during pressure oxidation (POX) of a refractory gold ore
Published in Canadian Metallurgical Quarterly, 2018
Igor Guzman, Steven J. Thorpe, Vladimiros G. Papangelakis
Liquid samples from the autoclave were taken during the experiments through an in situ filter (titanium 10 µm). Upon collection, the liquid samples were filtered again (PTFE syringe filter 0.45 µm, Fisher Scientific) and then bubbled with nitrogen to remove adsorbed oxygen and avoid further oxidation of species in solution. The composition of the samples was determined by inductively coupled plasma optical emission spectrometry (ICP-OES). The Fe(II) concentration was determined by redox titration using a K2Cr2O7 solution. The Fe(III) concentration was calculated as the difference between the total Fe concentration in solution determined by ICP-OES and the Fe(II) concentration determined by titration.
Structural and electrical investigations of novel CdFeO/(Bi,Pb)-2212 superconductor composite
Published in Phase Transitions, 2022
S. Abbas, H. Basma, R. Awad, M.S. Hassan
The Iodometric titration was employed for the determination of the oxygen content. The method consists of a two-step redox titration reaction [37,38]. In the first step, the superconductor sample is dissolved in Potassium Iodide (KI) acidic solution to achieve the reduction of copper to copper Iodide (CuI). In a second step, a back titration of the CuI was performed by using sodium thiosulphate (Na2S2O3) to determine the oxygen content [39]. The end point of titration was detected by using Potassium thiocyanate (KCSN) used as an indicator of iodometry.