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1.
本文简要地叙述了酸碱理论的发展过程,其中主要介绍了现代五大酸碱理论。即水-离子论、溶剂论、质子论、电子论和硬软酸碱概念,较详细地阐述和分析了它们各自的优点和局限性。 相似文献
2.
从软硬酸碱理论的起源出发,简要介绍软硬酸碱理论的建立背景、发展过程,并对其可能的应用范围做了讨论.最后结合人们对于软硬酸碱理论的认识和应用现状,做出总结和评价. 相似文献
3.
以酸碱电离理论和酸碱质子理论视角下盐类水解的教学设计为基础,阐述选取高中知识自然增长点作为教学资源帮助学生形成系统化学观,培养学生的深层理解能力和科学思维能力,从而达到教材做加法,学业做减法的可能性。 相似文献
4.
酸碱质子理论是普通化学中的重要模块。学习酸碱质子理论一般从弱酸水溶液入手,若将应用范围扩展为所有含质子的化合物,该理论将被赋予更多的内涵。在含质子的已知化合物中,Ka的范围十分宽广,跨越了100个数量级以上。哪种酸碱“最强”一直是学生间喜闻乐见的话题,以此话题出发,介绍了常见的超强酸、超强碱与相关概念及应用。这些概念的介绍不仅拓展了学生的视野,更能够加深学生对酸碱质子理论的理解,对未来分析化学、无机化学、有机化学的教育产生积极意义。 相似文献
5.
酸碱软硬度的理论研究 总被引:4,自引:0,他引:4
Pearson 从大量的实验事实归纳出的软硬酸碱原理广泛地应用于解释许多化学现象,还应用于评价和预料化学反应,极为简便、实用。然而,软硬酸碱原理的理论基础尚在不断地充实之中。近来微扰理论和密度泛函理论研究的结果表明:软硬酸碱能成功地描述化学反应,有明确的物理意义。现在(?)将定域硬度(或软度)和分子的化学活性定量地联系了起来。本文指出了酸碱软硬度键参数与物质性质定量研究的美好前景。 相似文献
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酸碱指示剂的发展方向 总被引:2,自引:0,他引:2
介绍了酸碱指示剂的基础知识和选择依据,重点介绍了目前天然植物色素在酸碱指示剂和酸碱滴定中的应用。同时,由于新技术的快速发展,基于纳米技术和DNA结构转变的无污染环保指示剂更加值得关注。 相似文献
8.
在多元外在表征教学理论的基础上,提出了酸碱中和滴定的教学设计,主要包括创设酸碱中和滴定实验情境、引入酸碱中和滴定概念与原理、介绍滴定管、选择指示剂、演示实验、使用Netlogo解释酸碱中和滴定等内容。研究结果表明该教学设计能帮助高职生更好地理解“酸碱中和滴定”知识。 相似文献
9.
以酸碱质子理论为基础,把分散在水和非水酸碱滴定各章节中的有关常数和公式系统地连贯起来,阐明了它们的关系和意义。 相似文献
10.
对分析化学酸碱滴定教学中引进酸碱滴定通式的问题进行了讨论。通过实例表明,将酸碱滴定通式引入到教学中,有助于学生更完整正确地把握酸碱滴定的理论。 相似文献
11.
Shingo Katayama Keiji Iwata Yuji Kubo Noriko Yamada 《Journal of Sol-Gel Science and Technology》2003,26(1-3):397-401
Solid acid-base properties of methylsiloxane-based inorganic/organic hybrids were controlled by incorporation of inorganic components other than Si into methylsiloxane networks. The effect of different inorganic components on the solid acid-base properties was estimated by first-principles calculations based on density functional theory (DFT). The deprotonation tends to occur in the order Si < Al < Nb inorganic components, suggesting that the acidity increases in the same order. Methylsiloxane-based hybrids with solid acid-base properties were also synthesized by incorporating inorganic components derived from metal alkoxides. Hammett indicators revealed that the solid acidity increased in the order Si < Al < Nb inorganic components, which was consistent with the results of first-principles calculations. Preliminary experiments revealed that the methylsiloxane-based hybrids also provided a solid basic nature by containing Ca and Y inorganic components derived from metal alkoxides. The acidic hybrids were found to have Brønsted acid sites from the FT-IR experiments of adsorbed pyridine on the hybrids. 相似文献
12.
Eugenia V. Kul''ko Aleksandra S. Ivanova Anna A. Budneva Evgenii A. Paukshtis 《Reaction Kinetics and Catalysis Letters》2006,88(2):381-390
Summary Acid-base properties of aluminas prepared by thermal treatment of a hydrated CTA-product at 600°C were studied. The CTA-oxides,
representing γ-Al2O3, were shown to contain terminal and bridged OH-groups. The concentration of the terminal OH-groups in the CTA-oxides was
found to exceed their concentration in γ-Al2O3 prepared by dehydration of the “precipitated” pseudoboehmite, whereas the concentration of the bridged OH-groups in the CTA-oxides
was lower than that in γ-Al2O3 prepared from pseudoboehmite. The total concentration of the surface Lewis acid sites in CTA-oxides varies within the limits
of 2.80-4.14 mmol/m2 and is essentially above that in g-Al2O3 (2.25 mmol/m2). The distinctive feature of the CTA-oxides is that their surface contains strong Lewis acid sites with nCO = 2220 and 2238 cm-1. The total concentration of basic sites in the CTA-oxides is lower than that in g-Al2O3, however, in contrast to g-Al2O3,they contain strong basic sites with nCDCl3 = 2200 cm-1. 相似文献
13.
Marina V. Bukhtiyarova Aleksandra S. Ivanova Lyudmila M. Plyasova Galina S. Litvak Anna A. Budneva Evgenii A. Paukshtis 《Reaction Kinetics and Catalysis Letters》2008,93(2):375-387
Hexaaluminates SrAl12O19, BaAl12O19 and LaAl11O18 were prepared by co-precipitation of soluble nitrates of Sr, Ba, or La and Al using NH4HCO3 as a precipitating agent with subsequent calcination at 700–1400°C. The samples were characterized by adsorption methods,
thermal analysis (TA and DTG), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy of adsorbed probe
molecules (CO and CDCl3). It was shown that calcination at 1200°C resulted in the formation of single-phase hexaaluminates in all the samples except
for LaAl11O18, where an additional phase was found. The specific surface area of the samples was obtained in the range 16–22 m2/g. After the treatment at comparable conditions, the total concentrations of both surface Lewis acid sites and basic sites
were found to increase in the series: BaAl12O19 < SrAl12O19 < LaAl11O18. However, the strongest basic sites were detected on the surface of BaAl12O19. 相似文献
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Yusuke Sunada Takashi Sue Hideo Nagashima 《Journal of organometallic chemistry》2006,691(14):3176-3182
Treatment of a titanium phosphinoamide, (Ph2PNtBu)2TiCl2 (1), with [Cp∗RuCl]4 in THF at room temperature afforded a TiRu heterobimetallic complex, of which crystallographic study showed the molecular structure to be a six-membered dimetallacyclohexane, Cp∗Ru(μ-Cl)(Ph2PNtBu)2TiO (3). A boat conformation of the dimetallacycle leads to effective linking of the two metal centers by two phosphinoamide ligands, and bridging of a chlorine atom over the TiRu axis. The TiRu heterobimetallics were synthesized by the reaction of 1 with Cp∗Ru(COD)Cl or Cp∗Ru(TMEDA)Cl, whereas no reaction occurred between 1 and Cp∗Ru(PCy3)Cl. A primary product of this reaction would be a trichloride, Cp∗Ru(μ-Cl)(Ph2PNtBu)2TiCl2 (2). In fact, careful treatment of 1 with [Cp∗RuCl]4 afforded 2 as the main product which was detected by NMR and ESI-MS spectra; 2 was converted to 3 in contact with 1 equivalent of water. 相似文献
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17.
Stephan Schulz Andreas Kuczkowski Heidi Saxell 《Journal of organometallic chemistry》2010,695(21):2281-2283
The Lewis acid-base adduct t-Bu3Al-SbMe3 (1), which was synthesized by reaction of equimolar amounts of t-Bu3Al and trimethylstibine SbMe3, was characterized by multinuclear NMR (1H, 13C) spectroscopy, elemental analyses as well as by single crystal X-ray diffraction. 相似文献
18.
酸碱型体分布系数计算的新方法 总被引:3,自引:1,他引:2
基于代数法,借助浓度对数图建立了一种计算酸碱型体分布系数的新方法。用该方法计算酸碱型分布系数,仅需对PH值及相关PKa值作加减衣简单的对数和指数运算,计算结果与代数法吻合。 相似文献
19.
Khalid Karim Agaddin Mamedov Mohammed H Al-Hazmi Naser Al-Andis 《Reaction Kinetics and Catalysis Letters》2003,80(1):3-11
Catalysts based on mixed oxide of MoVMn are active at relatively low temperature for oxidative dehydrogenation of ethane.
Incorporation of tungsten into MoVMn oxides enhances the catalytic activity. Enhancement of the activity is explained in the
light of acid-base interaction accompanied with a redox mechanism of surface reoxidation.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献