新课程背景下的化学实验教学的方法路径.doc

新课程背景下的化学实验教学的方法路径Under the background of new curriculum chemistry experimental teaching method of path实验是高中化学课程的重要组成部分，无论是必修教材还是选修教材，都将化学实验作为学生获取知识、发展能力的重要途径。但在教学现实中，由于新课程知识内容大量增加、教学课时减少、高考难度并没有降低等原因，使得实验这一“软模块”成了被挤压的对象。学生实验能力明显下降，学科素养明显滑坡。加强实验教学，并切实落实在教学行为上，具有重要的现实意义。Experiment is an important part of high school chemistry curriculum, whether compulsory teaching material or elective textbooks, will all the chemical experiment for students to acquire knowledge, develop ability of important ways. But in the reality of teaching, because of increased knowledge content of new curriculum, teaching hours, difficulty of the college entrance examination did not decrease, makes the experiment object of soft module has been squeezed. Students experimental ability decreased obviously, subject quality decline. Strengthen experiment teaching, and practical implementation in teaching behavior, has important practical significance. 一、全面规划，统筹实验教学内容One, comprehensive planning, experimental teaching contents as a whole 新课程突出了实验教学的地位，强化了实验在各章节中的引领、研究、获取结论、应用结论的作用。教学中，必须对实验教学内容进行全面规划，统筹安排，使之既与化学知识的教学密切配合，为讲解新知识提供鲜明、生动的感性认识，又能有步骤、循序渐进地培养学生的实验能力。New curriculum highlights the position of experiment teaching, to strengthen the experiment led in the chapters, research and conclusion, the application effect is obtained. Teaching, experiment teaching content must be comprehensive planning, overall arrangement, make the teaching closely cooperate with both the knowledge of chemistry, to explain the new knowledge provides a bright and vivid perceptual knowledge, and step by step, gradually cultivate the students experiment ability. 以苏教版高中化学必修1的教学为例，我们设想将实验能力的培养分为三个阶段：To Sue version of high school chemistry compulsory teaching 1 as an example, we assume the experimental ability is divided into three stages: 第一阶段，在初中化学的基础上进行基本操作训练，培养学生掌握操作、观察、描述、记录的方法和能力。根据教材内容，具体安排如下实验：（1）药品取用、加热、溶解、过滤、结晶、粗盐提纯；（2）萃取分液、蒸发蒸馏、纸上层析、白酒度数的测定；（3）常见胶体的制备、常见阴阳离子检验；（4）溶液配制。将单项训练与综合练习相结合，基本操作与具体实验相结合的方法，可以使学生的操作技能在具体实验中得到运用，较好地调动学生学习的积极性，防止出现因单纯进行基本操作训练使学生学习兴趣下降的现象。Conducted on the basis of the first stage, in the junior middle school chemistry basic operation training, trains the student to master the methods of operation, observation, description and record and ability. Experiment according to the teaching material content, specific arrangement as follows: (1) drug use, heating, dissolving, filtration, crystallization and purification of coarse salt; (2) the upper extraction liquid evaporation, distillation, paper chromatography, wine degree determination; (3) common gel preparation, common ion of Yin and Yang of inspection; (4) solution preparation. Combining individual training and comprehensive practice, basic operation combined with a concrete experiment method, can make the students skills in the concrete to be used in the experiments, the better to mobilize the enthusiasm of students learning, prevent from simple basic operation training so that the students interest in learning decline phenomenon. 第二阶段，通过一定数量的演示实验、边讲边实验、学生独立实验，在巩固强化单项操作技能的同时，培养学生按照实验步骤独立完成简单实验的能力，同时学会凭借分析、综合、抽象、概括等思维活动得出实验结论的方法。根据教材内容，具体安排如下实验：（1）常见金属及其化合物（钠、镁、铝和氧气的反应，铝、氧化铝、氢氧化铝的两性，铁的氢氧化物的制备，碳酸钠和碳酸氢钠与酸及稳定性比较，焰色反应等）；（2）氯气和二氧化硫性质的比较（氯水分别与淀粉KI、NaOH、等的反应，的制取及性质等）；（3）氨气和硝酸（氨气的制备喷泉实验，N与水的反应，铜和浓、稀硝酸的反应等）。这一阶段，宜淡化学生实验与演示实验的界限，尽量将学生实验融于新课程的教与学的全过程，充分发挥实验在激发兴趣、引发思维、形成概念、理解理论、探究性质中的重要作用。The second stage, through a certain number of demonstration experiment, talking and experiment, students independent experiment, while also strengthen individual skills, training students in accordance with the experimental steps do simple experiment independently, at the same time learn to rely on analysis and synthesis, abstraction and generalization method of thinking activity experiment conclusion. Experiment according to the teaching material content, specific arrangement as follows: (1) the common metals and their compounds (sodium, magnesium, aluminum and oxygen reaction, amphoteric aluminum, alumina, aluminum hydroxide, the preparation of iron hydroxide, sodium carbonate and sodium bicarbonate compared with acid and stability, flame color reaction, etc.); Comparison (2) the nature of chlorine and sulfur dioxide, chlorine water respectively with starch - KI, NaOH, reaction, the preparing and properties, etc.); (3) ammonia and nitrate, ammonia preparation fountain experiment, N reaction with water, the copper and thick, thin nitric acid reaction, etc.). This one phase, should be played down the boundaries of students experiment and demonstration experiment, student experiment try to dissolve into the whole process of teaching and learning of the new curriculum, and give full play to the experiment on stimulating interest, thinking, concept formation, understanding theory, explore the important role of character. 第三阶段，重点是培养学生设计实验的能力。要求学生独立设计实验方案、完成实验操作、记录和分析现象、得出结论，培养学生应用知识解决简单的实际问题的能力。这一阶段，主要由教师根据教学内容或实验中的异常现象提出问题，让学生围绕化学问题展开探究活动，在问题的驱使下，寻找证据、利用证据对问题进行解释，从而使自己的认识获得提高，认知获得发展。The third stage, the key is to cultivate students ability to design experiments. Requires students to design experiments independently plan, complete experimental operation, record and analysis of the phenomenon, concluded that training students ability of applying knowledge to solve simple practical problems. This stage, is mainly composed of teachers according to the teaching contents or the anomaly experimental questions, lets the student taking the inquiry activity of chemical problems, under the drive of problem, looking for evidence to explain the problem, the use of evidence, to give their own understanding, cognitive development. 二、不断实践，优化实验教学方法Second, and constantly practice, optimizing experimental teaching method （一）强化基本操作训练是培养实验能力的基础(a) strengthening basic operation training is the foundation of training experiment ability 正确的实验操作是完成实验并获得良好实验效果的必要条件。我们的做法是：合理安排基本操作训练的内容。按照由易到难、由简到繁的原则，对每一项基本操作训练，均按照“单项操作组合操作简单实验”的次序进行组合。这样，不仅训练了基本操作，还实现了化学知识教学与实验技能培养的同步。具体的教学程序是：明确学习任务教师讲解原理或要领教师示范操作学生模仿（单一的动作练习）连续的操作练习（综合练习）完成简单实验（操作技能的应用）讲评。The correct experiment operation is completed the necessary conditions and obtain good experiment effect. Our approach is: reasonable arrangement of the content of the basic operation training. From easy to difficult, from simple to complex, the principle of the each basic operation training, all according to the single operation, combination operation, simple experiment of the order. In this way, not only training the basic operation, also implements the teaching of chemical knowledge and experimental skills of synchronization. Specific teaching program is: clear learning task, teachers explain principle or main point - teachers demonstration, students imitate the action practice (single) - continuous operation practice (general practice) - to do simple test application (skills) - evaluation. （二）正确处理演示实验、学生实验之间的关系，充分利用化学实验引领化学教学(2) correctly handle the relationship between the demonstration experiment and student experiment, make full use of the chemical experiment guide chemistry teaching 演示实验是在教师或教材设计好的步骤中进行的实验，它是帮助学生形成化学思维的一种有效形式。通常，下列情况宜进行演示：（1）原理简单，单纯展示化学现象的实验；（2）实验操作复杂、控制有难度，或污染严重的实验；（3）激发兴趣，引入课题的实验。教师的操作应该给学生以示范，设计恰当的问题链，引导学生的思维由表及里、由浅入深，是提高演示实验质量的重要方法。Demonstration experiment are in good teachers or teaching material design steps in experiments, it is to help students form an effective form of thinking in chemistry. In general, should be demonstrated in the following circumstances: (1) the principle of simple, pure display chemistry experiment; (2) the difficulty of the complex experimental operation, control, or polluted experiment; (3) stimulate interest, the introduction of the topic. Operations the teachers should give students in demonstration, design appropriate problem chains, its excellent guide students thinking, it is an important method to improve the quality of the demonstration experiment. 比如，胶体是一个比较抽象的概念，恰当地运用演示实验，可以达到活跃课堂气氛、活化学生思维的作用。教学时，教师首先提出问题：硝酸银和氯化钠溶液混合可以看到什么现象？接着，在10 mL 0.01 mol/L 溶液中滴入45滴0.01 mol/L NaCl，要求学生观察现象。然后，提问：为什么没有沉淀？如何证明AgCl颗粒的大小？引导学生得出结论：用可见光照射，有丁达尔现象。最后，引出胶体概念。学生实验是在实际情境中观察、发现问题，通过思考、探究，寻找答案。它可以训练学生的动手能力，培养学生的科学探究意识，引导学生关注过程与方法，培养良好的学科思维习惯。有些实验如果一开始就让学生动手操作，由于学生实验原理不清、思维指向不明确，必然造成课堂的混乱，极大地影响实验的效果。只有在原理清楚、目标明确的前提下，让学生动手实验，才能调动学生积极参与。For example, colloid is a more abstract concept, appropriate use of demonstration experiment, active classroom atmosphere can be achieved, the action of activating students thinking. Teaching, the teacher ask questions first: silver nitrate and sodium chloride solution as you can see what phenomenon? Then, in 10 mL of 0.01 mol/L solution into 4 5 drops 0.01 mol/L NaCl, students are required to observe phenomena. Then, lift to ask: why no precipitation? How to prove that AgCl particle size? Guides the student to come to the conclusion: irradiation with visible light, butyl phenomenon. Finally, which leads to the concept of colloid. Students experimental observation, found that the problem is in the actual situations, by thinking, explore, looking for the answer. It can train students practical ability, to cultivate the students science inquiry consciousness, guides the student to focus on the process and method, develop good thinking habit of discipline. Some experiments if let students hands-on at the beginning, because the student doesnt know the experimental principle, thinking to not clear, is bound to cause chaos in the classroom, greatly influence the experiment result. Only in principle under the premise of clear, clear goal, let the students experiment, to mobilize students active participation. 比如，教学的性质，应该让学生利用已有知识，在实验操作中获得新的知识For example, the nature of the teaching, should let the students to use knowledge, gain new knowledge in the experimental operation - 首先，引导学生从化合价分析可能具有的化学性质：Firstly, guide the student from the valence analysis may have chemical properties: 接着，设问：能否设计实验证明推理是否正确？Then, rhetorical questions: can design experiments prove that reasoning is correct? 提供药品：二氧化硫、高锰酸钾、溴水、氢硫酸。学生设计方案并实验，完成下表：Access to medicines: sulfur dioxide sulfuric acid, potassium permanganate, bromine water, hydrogen. Students design and experiment, complete the table below: 在这样的过程中，学生利用已学知识推测的性质，真正实现了知识的自主构建。实践表明，通过一个个小实验，学生能够在相对开放的思维空间内去完成自己对新知识的探索，通过自己的所思、所做、所见、所想，获得知识、形成技能，建立一种科学的思维方式，从而印象深刻、记忆牢固、应用灵活。In this process, the nature of the students to learn knowledge and use have been speculated that, truly achieve the independent construction of knowledge. Practice shows that through the small experiment, students can in a relatively open thinking space to accomplish their exploration of new knowledge, through their own thinking, do, see, think, acquire knowledge and skill formation, establish a scientific way of thinking, and impressive, memory strong, flexible application. （三）不断改进实验，探究方法技巧，使操作更简单、现象更明显(3) improving experiment, explore techniques, make the operation more simple, the phenomenon is more obvious 鲜明的实验现象是取得好的实验效果的前提。一个现象若隐若现、似是而非的实验，必然挫伤学生观察的积极性，影响课堂的流畅性。In experimental phenomena is the precondition of good experimental results. A phenomenon is like concealed, specious experiments, will inevitably affect the enthusiasm of students to observe, affect classroom fluency. 比如，酯化反应实验中生成的酯是无色透明的液体，必须仔细观察方可发现分层现象。但如果向收集酯的试管中沿管壁小心加入紫色的石蕊试液，试管中会出现明显的三色环现象上红、中紫、下蓝，分层十分鲜明。振荡后变为两层，上层无色液体的高度明显缩短，下层仍呈蓝色，很好地说明了饱和碳酸钠溶液的作用。Esterification experiments, for example, the generated ester is colorless transparent liquid, must observe carefully in order to found the stratification. But if you care to collect ester tube along the tube wall to join the purple litmus test solution, test tube will appear obviously on the three color ring phenomenon - red, purple, blue, layering is very bright. Oscillation after into two layers, the upper clear liquid height significantly shortened, still dark blue, lower well illustrates the role of the saturated sodium carbonate solution. 三、强化探究，培养实验研究能力Three, strengthening the explore and cultivate ability of experimental study 杜威认为，除了探索研究，知识没有别的意义。实验并不只是培养使用仪器和实验操作的能力，更加重要的是让学生通过实验、分析、研究，在这一过程中形成化学素养。化学课堂中的探究教学，其流程一般是学生通过阅读教材，产生问题，提出猜想，制订计划，动手实验，收集证据，得出结论，反思评价，交流讨论。探究内容的选择可大可小，可以整体也可以局部，具体问题的探究流程也不一定包含上述全部要素。但事事探究、处处探究，肯定是不可取的。Dewey think, in addition to explore research, knowledge has no other significance. Experiment not only develop instrumentation and experimental operation ability, more important is to let students through the experiment, analysis, research, formed in the process of chemical literacy. Inquiry teaching in chemistry classroom, its process is the student by reading the textbook, general problems, put forward hypothesis, planning, hands-on experiments, collecting evidence, the conclusion, reflection, discussion. Explore the choice of content but can small, can the overall local, specific questions of process does not necessarily include all of the above factors. But explore everything, everywhere, is certainly not desirable. （一）围绕重点内容展开探究(a) revolves around the key content to explore 探究的核心问题必须围绕学习应掌握的重点知识和技能。如此，才能在探究的同时较好地实现三维目标。Inquiries must revolve around the core issue of study should grasp the key knowledge and skills. So, to explore the better realization of three-dimensional targets at the same time. 例如，苏教版高中化学必修1“氮氧化物的产生及转化”一节，涉及氮气的分子结构、物理性质、化学性质及氮氧化物的性质及转化等，选取哪个点进行探究呢？化学性质中的“雷雨发庄稼”这一情境，很好地融合了氮气的氧化及氮氧化物间转化这一重点内容，作为探究点是非常合适的：（1）提出问题：说说“雷雨发庄稼”的科学道理。（2）学生交流讨论：。（3）学生设计方案检验推理的正确性。（4）教师演示：按课本装置图演示氮氧放电反应的实验。（5）学生归纳现象：装置内产生电火花，嗤嗤作响，有红棕色气体产生；加水后红棕色消失，用蓝色石蕊试纸检验，试纸Sue includes, for example, high school chemistry compulsory 1 nox generation and transformation section, related to the molecular structure of the nitrogen, physical properties, chemical properties and of the nature and transformation of nitrogen oxides, etc., which explore the point selection? Thunderstorm crops in the chemical properties of this situation, good convergence between the oxidation of nitrogen and nitrogen oxides into the key content, as the inquiry is very right: (1) question: about crops thunderstorm scientific reason. Discussion: (2) students. (3) students test design scheme reasoning is correct. (4) teachers demonstration, according to the textbook figure demo nitrogen oxygen discharge experiment device. (5) the student induction phenomenon: device that produce electrical discharge, sputtering, red brown gases; Red brown disappear after adding water, use blue litmus test, test paper 通过这样的科学探究，学生在结论的获取和方法的体验过程中，掌握了氮气与氧气的反应，掌握了NO、N的物理化学性质。如果安排学生探究氮气的物理性质或氮气在空气中的含量，其作用和价值就要大打折扣了。Through such a scientific inquiry, students at the conclusion of the process, and method of experience for mastery of the nitrogen and oxygen reaction, mastered the physical and chemical properties of NO, N. If arrange students to explore the physical properties of nitrogen or the nitrogen content in the air, its function and value is going to sell at a discount greatly. （二）注重对探究结论合理性的反思与评价(2) pay