“化学能转化为电能”教学设计

1教学目标 (1)知识与技能:理解原电池原理,初步学会书写电极反应方程式,探究原电池的形成条件. (2)过程与方法:通过对锌与稀硫酸反应中的化学能能否转化为电能的实验探究,让学生理解原电池的概念和工作原理;通过对原电池形成条件的实验探究、问题讨论,培养学生观察、分析问题的能力,特别是创新思维能力.     

“化学反应的利用”教学设计

“化学反应的利用”包含两部分内容:利用化学反应制备新物质,化学反应为人类提供能源。分2课时进行。1教学目标(1)知识与技能①掌握实验室制备氯气的原理和尾气处理方法,了解制备装置及收集方法。②了解原电池的工作原理。(2)过程与方法通过“活动.探究-氯气的制取和原电池的工作原理”学会运用实验、观察获取信息并分析推理。(3)情感态度价值观通过教材等途径为学生提供丰富的材料,开拓视野,使学生从多个角度体会化学科学与人类文明和社会发展的密切关系,提升对研究化学反应应用价值的认识。2教学流程教师活动学生活动设计意图就上一问题作答,引出化学能→电能;布置探究任务-利用所给仪器和试剂进行实验,解决下列问题:(1)化学能能否转化为电能?你组装的装置实现了吗?(2)在装置中你还有什么新发现?依据所给用品与试剂(干电池、导线、电流计、锌板、铜板、稀硫酸、反应器)进行探究性实验并观察实验现象(1)通过让学生分组设计完成实验,为学生提供合作学习机会提高实验技能及观察能力;(2)在探究学习活动中体验科学发现的过程,尝试探究成功的快乐对学生实验进行评价用Flash课件展示原电池工作原理小结原电池工作原理分析现象,探究原电池工作原理(组内讨...     

氧化还原反应平衡与移动的实验研究——以硫酸铁与碘化钾反应为例

以Fe3+与I-的反应为例,将具象的原电池与抽象的化学平衡概念相结合,将氧化还原反应、化学平衡及其移动、原电池等多个知识点同时呈现,有助于学生建构系统化、结构化的综合知识网络。改进了实验装置和试剂用量,确定了该实验课堂演示的最佳条件,为教师教学提供了教学建议。     

发展学生化学学科核心素养的“化学能与电能”教学*——小车为什么会跑起来

“化学能与电能”是高中化学必修阶段的核心内容,是发展学生化学学科核心素养的重要知识载体。围绕“小车为什么会跑起来”的真实问题,利用铜锌原电池驱动小车的实验现象,引导学生分析原电池的工作原理,探究原电池的构成条件,充分发展学生的化学学科核心素养。     

利用手持技术探究原电池“电极反转”双模型的反应机理

基于手持技术表征原电池基准态与极端态工作原理的差异性,继而探究铁和铝分别与铜在浓硝酸中构成的2种极端态原电池在发生电极反转时硝酸浓度的临界值。通过双模型对比实验,帮助学生更加直观、准确、深入地建构原电池模型,同时丰富学生对元素周期律、金属活动性以及氧化还原反应等关联性知识的认知与理解。     

微观反应 宏观显现*—— 原电池实验和碳酸钠与盐酸分步反应的可视化改进

鉴于演示实验的重要教学价值,通过剖析教材中2例演示实验--“原电池实验和碳酸钠与盐酸分步反应”可视化效果不佳的成因,用电极绞合法和粉笔吸附法巧妙地加以改进,可以简单有效地展现实验现象。实验操作简便、现象明显,具有很好的推广价值。     

促进能量观功能化的教学策略研究——以高中必修“原电池”教学为例

分析了必修阶段原电池教学内容对促进学生能量观发展的价值,提出理解原电池原理和建构原电池装置的一般思路和方法是实现能量观功能化的前提条件。阐述了在原电池新授课阶段,通过优选原电池教学模型,采取学生探究设计原电池,建构原电池认识模型等教学策略,促进学生观念的建构与功能化。     

锌铜原电池中锌片上气泡的成因分析与实验改进*

简要分析了Zn-Cu原电池演示实验中Zn片电极产生气泡的原因,并用琼脂凝胶法改进了实验。改进后的实验有效地避免了Zn片上H2的逸出,使得实验现象与理论推导一致,具有较好的推广价值。     

整合多重表征 促进概念深度理解——以“原电池”为例

有效整合多重表征,是促进学生科学概念深度理解的一种有效策略。本研究整合了科学教育领域中的3个多重表征框架的内容,对高中必修模块的“原电池”进行了教学设计。首先引导学生依次学习原电池的宏观装置、微观原理和电极符号,初步建构原电池概念,之后基于氢氧燃料电池关联表征,让学生建构原电池的装置原理二维模型图,理解原电池概念,最后依托生活中的纽扣电池应用二维模型图实现表征转换,解决实际问题,实现对原电池概念的深度理解。     

对氢氧燃料电池实验的研究与改进

1 介绍一种自制教具--多用途原电池演示板 用厚约1.2 cm的木板制作30 cm×35 cm的小木板若干块,演示用带脚,可以直立,便于观察;学生分组实验用不带脚,平放桌面使用.小木板油漆好待用.用一只双掷开关代替原来的2只单刀开关,检验电流除用二极管外,再增加电珠和蜂鸣器各一只,供作对比实验,同时增加实验的趣味性.     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。