基于“实验-性质-原理”三元整合策略的高三化学微专题复习研究——以“弱电解质的电离与电离平衡”为例

概述了"实验-性质-原理"三元整合策略的内涵及在高三化学微专题复习中的实施应用。以"弱电解质的电离与电离平衡"为例,以"区别相同浓度的盐酸、醋酸"实验探究活动为驱动任务,结合盐酸、醋酸与镁反应不同时间段的现象,学生根据反应原理预测可能原因,画图分析c（H+）变化,完成强、弱电解质性质的"宏观-微观-符号"三重表征。引入电离平衡常数的数据分析活动,穿插"原因解释"的答题策略及规范训练、图表阅读、基于控制变量法设计实验方案等学习任务,为高三微专题复习提出教学建议。     

物理化学教学中是否一定要定义a±?

电解质活度的问题是物理化学中的一个基本问题,涉及的范围较广。而我国现行的《物理化学》教科书中,论述电解质活度定义时,认为电解质在溶液中以离子形式存在,而单独离子的活度和活度系数a_+、a_-、γ_+、γ_-则无法用实验测量。因此需定义能用实验方法测定的电解质平均活度a_±、平均活度系数γ_±及与之有关的平均浓度m_±。     

光电催化降解活性艳红K-2BP中电解质NaCl和Na2SO4的作用研究

以TiO₂/Ti为阳极, Ti网为阴极, 研究了活性艳红K-2BP在NaCl和Na₂SO₄电解质中的降解情况, 深入探讨了两种电解质在光电催化降解染料中的作用, 研究了电解质浓度、溶液pH值的影响, 并讨论了在混合盐电解质存在下, 活性艳红K-2BP的降解行为. 研究表明, 以NaCl为电解质时, Cl^－会转化为氧化性很强的活性氯, 活性氯及光电的共同作用, 加速了染料的降解. 以Na₂SO₄为电解质时, SO₄^2－在光电的作用下将发生两类反应, 一部分SO₄^2－捕获光生空穴和HO•, 对光电催化降解染料起抑制作用; 另一部分SO₄^2－将发生反应生成H₂O₂, 对染料降解起促进作用. 关键词 光电催化; 活性艳红K-2BP; TiO₂/Ti电极; 电解质     

光电催化降解活性艳红K-2BP中电解质NaCl和Na2SO4的作用研究

以TiO₂/Ti为阳极, Ti网为阴极, 研究了活性艳红K-2BP在NaCl和Na₂SO₄电解质中的降解情况, 深入探讨了两种电解质在光电催化降解染料中的作用, 研究了电解质浓度、溶液pH值的影响, 并讨论了在混合盐电解质存在下, 活性艳红K-2BP的降解行为. 研究表明, 以NaCl为电解质时, Cl^－会转化为氧化性很强的活性氯, 活性氯及光电的共同作用, 加速了染料的降解. 以Na₂SO₄为电解质时, SO₄^2－在光电的作用下将发生两类反应, 一部分SO₄^2－捕获光生空穴和HO•, 对光电催化降解染料起抑制作用; 另一部分SO₄^2－将发生反应生成H₂O₂, 对染料降解起促进作用. 关键词 光电催化; 活性艳红K-2BP; TiO₂/Ti电极; 电解质     

离子凝胶反应法制备壳聚糖/N,O-羧甲基壳聚糖微球

以一氯乙酸与壳聚糖反应形成N,O-羧甲基壳聚糖两性聚电解质,分光光度法测定其等电点IEP=2．86。以此两性聚电解质与壳聚糖可以在一定条件下形成微球,光学显微镜和电子显微镜测试表明,控制两种聚电解质配比可以制备不同粒径大小的微球,而超声功率对微球粒径的影响较小。红外光谱测试表明微球中N,O-羧甲基壳聚糖羧基以羧酸根形式存在,分光光度与电导法联合测定表明两种聚电解质以离子凝胶作用形成微球,其最佳制备条件为IEP（CM-CHITOSAN）〈pH〈pKa（CS）,在此较宽的pH值范围内微球可稳定存在。     

全氟卤代烷在氯磺酸中的电化学反应

本文报道了以氯磺酸钾为电解质, 铂为电极, 进行氯磺酸的阳极氧化, 产生过氧二磺酰氯, 并和阳极池内α,ω-氯磺含氟烷进行反应, 生成相应的氯磺酸酯, 反应主要副产物为α,ω-二氯全氟烷, 在阳极有大量氢气逸出, 并得到碘。     

脱乙酰甲壳质和卡拉胶的稀溶液反应

本文研究了脱乙酰甲壳质和卡拉胶为稀溶液时的电离及两者之间的相互作用。卡拉胶在溶液中呈强酸型聚电解质行为,而脱乙酰甲壳质呈弱碱型聚电解质行为并随脱乙酰度提高而碱性下降。脱乙酰甲壳质和卡拉胶的稀溶液反应生成不溶于水的白色沉淀。浊度测量显示,在pH值低于4时,反应是化学计量的,说明这时它们之间的反应主要是通过静电相互作用而形电解质复合物沉淀。当pH值较高时,反应偏离化学计量结果。     

基于“宏观辨识与微观探析”核心素养培养的“电解质的电离”教、学、评一体化实践

“电解质的电离”作为高中化学的重要学科内容,受到教师广泛重视,但是在实践中存在着教学效果不理想的情况,主要表现是学生未建立微观认识物质的视角,这与教师在教学过程中过于关注电解质概念,进行具体性知识教学而忽视具有核心素养培养功能的电离概念的教学有直接关系。从素养发展来看,“电解质的电离”是培养学生“宏观辨识与微观探析”素养方面时重要的内容载体,而教、学、评一体化的落实情况决定“电解质的电离”这一核心概念的教学效果。通过凸显水的作用、导电性实验的功能化处理、加强电离概念的功能化教学等区别于传统教学的尝试,在教、学、评一体化的实践中取得了较好的教学效果。     

金电极析氢反应过程中吸附氢原子的表面扩散及复合反应动力学研究

用特别设计的以平面金电极为工作电极,以Nafion膜为固体电解质的实验装置,对金电极析氢反应过程中吸附氢原子的表面扩散及吸附氢原子复合为氢分子的反应进行了定量研究,发现吸附氢原子在金表面上的扩散及复合反应引起了电流增加.对这一随时间变化的电流增加数据进行计算机模拟和数值拟合,得到金电极析氢反应中吸附氢原子的表面扩散系数、复合反应常数及其它动力学参数,并对数据进行了讨论.     

无机-有机杂化聚合物电解质的制备与电化学性能

以有机改性聚硅氧烷为单体加入液态电解质通过紫外光辐射固化制备了无机有机杂化聚合物电解质.含有丙烯酸酯端基的有机改性聚硅氧烷单体是通过正硅酸甲酯(TMOS)的水解缩合反应产物与丙烯酸2羟乙酯(HEA)进行脱甲醇反应合成的.它是一种多官能团单体,其结构通过核磁共振氢谱(1HNMR)分析、红外光谱(FTIR)分析及二氧化硅分析进行了表征,分子式可表达为SiO1.143(OH)0.016(OCH3)1.339(OCH2CH2OCOCHCH2)0.357.无机有机杂化聚合物电解质的电化学性能通过交流阻抗和循环伏安法进行了表征.其离子电导率随着液态电解质含量的增大而提高,当液态电解质含量为85wt%时,电导率在22℃为5.5×10-3Scm-1,在-23℃也能达到1.1×10-3Scm-1.界面电阻经过开始2天的增大后达到稳定,电化学稳定窗口超过5.0V,不锈钢电极上锂的电化学沉积与剥离循环可逆性很高.     

血橙呈现“红色”的探讨

血橙因果肉颜色呈血红色而得名,血橙果肉的颜色深浅取决于花色苷的含量。该含量容易受温度、光照、空气湿度、pH等因素影响而发生变化。从果肉“红色”的形成、“红色”的深浅程度、血橙对人体健康的影响等3个方面对血橙的“红色”进行探讨,以期为读者科普血橙中蕴含的化学知识,感受化学与生活的紧密联系。     

Influence of the composition of carriers based on ZrO<Subscript>2</Subscript> and Al<Subscript>2</Subscript>O<Subscript>3</Subscript> on the properties of cobalt-containing catalysts on the selective reduction of NO with methane

A series of cobalt-containing granulated and structured catalysts based on zirconium and aluminum oxides has been studied. The optimum composition of binary oxide samples (80% ZrO₂ − 20% Al₂O₃) for the selective reduction of nitrogen monoxide with methane (84% conversion of NO achieved at 320 °C) has been determined. The activity of the structured catalysts depends on both the composition of the secondary carrier (ZrO₂, Al₂O₃, and their mixture) and on the nature of the skeleton of the cellular structure (cordierite, kaolin-aerosil). __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 43, No. 4, pp. 237–241, July–August, 2007.     

Studies on the Constituents of Paris Formosana Hayata Part II

Methyl palmitate (I), methyl stearate (II), stigmasterol (III), β-sitosterol (IV), (O -acyl)-β-D -glucopyranosyl-(1→3)-stigmasterol (V), (O -acyl)-β-D -glucopyranosyl-(1→3)-β-sitosterol (VI), β-D -glucopyranosyl-(1→3)-stigmasterol (VII), β-D -glucopyranosyl-(1→3)-β-sitosterol (VIII), β-D -ecdysone (IX), diosgenin-3-α-L -rhamopyranosyl-(1→2)-[α-L -arabinofuranosyl-(1→4)]-β-D -glucopyranoside (X), diosgenin-3-O -β-chacotrioside (dioscin) (XI), and diosgenin-3-O -α-L -rhamnopyranosyl-(1→4)-α-L -rhamnopyranosyl-(1→4)-[α-L -rhamnopyranosyl-(1→2)]-β-D -glucopyranoside (XII) were isolated and characterized from the stems of Paris formosana Hayata (Liliaceae).     

The effect of temperature on the formation of titanium dioxide structures on γ-Al<Subscript>2</Subscript>O<Subscript>3</Subscript> surface

The effect of calcination temperature of hydrated gamma-aluminum oxide on the phase formation of surface structures and the content of titanium in them in the course of successive treatment of the initial matrix with TiCl₄ and H₂O was determined.     

“S-O-R”精细加工策略提升“外显”“内隐”知识的思考

依据托尔曼"S-O-R行为模型",利用"单元设计组织、教学策略、内隐知识、教学反馈"等外部刺激,引起学生知识加工过程中"概括、类比、产生冲突、期望"等中介变量改变,将"外显""内隐"知识均纳入到知识网络同时促成有效学习略作探讨。     

Influence of ThO<Subscript>2</Subscript> on the photocatalytic activity of TiO<Subscript>2</Subscript>

Microcomposites consisting of TiO₂ (or Ce-doped TiO₂) and ThO₂ (0.5–2% of the TiO₂ mass) are produced by sol-gel synthesis of TiO₂ in presence of ThO₂. X-ray diffraction study reveals the effects of ThO₂ (compared to the ThO₂-free TiO₂, obtained by the same method) on the anatase interplanar distances, crystallites size and phase composition. The photocatalytic tests in presence of the composites under UV irradiation reveal an increase of the Malachite Green degradation rate constant. The effect depends on the Th relative content, temperature of annealing of the catalyst and addition of other doping agent. The highest photocatalytic activity is observed for TiO₂ obtained at 550°C and containing 1% ThO₂. The composite exhibits activity in dark, also. The presence of Ce⁴⁺ ions is not an obligatory requirement for the realization of the ThO₂ effect. The reported results suggest that the radioactivity of the Th and/or its decay products is one of the main factors responsible for the increased photocatalytic activity of TiO₂.      

Effects of BaCl<Subscript>2</Subscript> on slow vacuolar ion channels on radish by patch-clamp

The effects of BaCl₂ on slow vacuolar (SV) currents of radish are studied by using the whole-vacuolar patch-clamp recording mode. The Ca²⁺-dependent SV channel can be activated by cytosolic Ca²⁺. When 1 mmol/L BaCl₂ is added into pipette solution, SV currents are suppressed remarkably. Then adding BaCl₂ of different concentrations into the bath solution, SV currents reflect different effects. The results show that BaCl₂ with a lower concentration (<3 mmol/L) promotes the channel currents and the currents are saturated when BaCl₂ concentrations are between 1 μmol/L and 1 mmol/L, but BaCl₂ with higher concentration (≥ 3 mmol/L) inhibits SV currents.     

QSPR study on pK<Subscript>a</Subscript> values of N-methoxy-polynitroaniline derivatives

A QSPR study is presented for acidities of thirteen N-methoxy-polynitroaniline derivatives. Hammett σ values are known for meta and para substituents, and in the present study values are introduced for ortho-substituents in these N-methoxy-polynitroaniline derivatives. Hammett σ values for ortho-substituents in these N-methoxy-polynitroaniline derivatives were obtained by multiplying para values with 0.65.     

Impact of environmental conditions on the sorption behavior of radionuclide <Superscript>60</Superscript>Co(II) on MnO<Subscript>2</Subscript>

The fate and transport of toxic metal ions and radionuclides in the environment is generally controlled by sorption reactions. The removal of ⁶⁰Co(II) from wastewaters by MnO₂ was studied as a function of various environmental parameters such as shaking time, pH, ionic strength, foreign ions, and humic substances under ambient conditions. The results indicated that the sorption of ⁶⁰Co(II) on MnO₂ was strongly dependent on pH and ionic strength. At low pH, the sorption of ⁶⁰Co(II) was dominated by outer-sphere surface complexation and ion exchange with Na⁺/H⁺ on MnO₂ surfaces, whereas inner-sphere surface complexation was the main sorption mechanism at high pH. The presence of HA/FA enhances ⁶⁰Co(II) sorption at low pH values, whereas reduces ⁶⁰Co(II) sorption at high pH values. The Langmuir and Freundlich models were used to simulate the sorption isotherms of ⁶⁰Co(II) at three different temperatures of 298.15, 318.15 and 338.15 K. The thermodynamic parameters (ΔH ⁰, ΔS ⁰ and ΔG ⁰) calculated from the temperature dependent sorption isotherms indicated that the sorption process of ⁶⁰Co(II) on MnO₂ was endothermic and spontaneous.