Production of carbon dioxide lecture notes in junior middle school chemistry laboratory (1) I. teaching material analysis
1. Status and role
This topic plays a very important role in the whole chemistry learning process. When preparing a certain gas in the laboratory, it is the best teaching material to cultivate students' thinking about drug selection, device design and experimental methods. Doing this lesson well will have a far-reaching impact on students' future study of elemental valence knowledge, basic chemical experiments and the cultivation of inquiry ability.
As far as this lesson is concerned, it is not only the consolidation and promotion of oxygen-making knowledge in the laboratory, but also the construction of gas-making knowledge II. Through the study of this course, students should be able to form a complete knowledge system of chemical gas production in junior high school, including drug selection and exploration, which can play a comprehensive guiding role in learning related knowledge in the future.
2. Teaching emphases and difficulties
Teaching emphasis: research on chemical reaction principle, experimental device and preparation method of carbon dioxide in laboratory.
Key breakthroughs: (1) Through demonstration experiments and student experiments, teachers and students jointly determine the drugs and reaction principles for preparing carbon dioxide in the laboratory; (2) Students demonstrate experiments and combine them with group experiments, and feedback and correct them in time.
Difficulties in teaching: determining the drugs to take carbon dioxide in the laboratory. .
Difficulty breakthrough: through the process of divergence and convergence of thinking, the exploration process of drug selection for carbon dioxide production in the laboratory is completed.
Second, the analysis of learning situation
Students learned the laboratory preparation method of oxygen and were familiar with the preparation and collection of gas. They know that the collection method of gas is related to the physical properties of gas, and the physical properties of gas can produce CO2 reaction. They think of the burning of charcoal, the reduction of copper oxide by carbon and the decomposition of carbonic acid, but they have no knowledge about the reaction between marble and dilute hydrochloric acid. The basic situation of students in a class is: the quality is uneven, there are many students with medium level and nearly a dozen students with poor foundation. Try to learn some basic knowledge in the teaching process. For the part of improvement, after-school consolidation exercises can be used as improvement questions. It is also necessary to improve students' interest in learning through experiments, and teachers should carefully organize them, such as questioning counseling and roving guidance.
Third, the teaching objectives
1, knowledge and skills:
(1) can tell the method and design idea of gas production in the laboratory; The chemical reaction principle of carbon dioxide generation in the laboratory can be expressed by chemical equations, and the knowledge system of gas production can be established to independently complete the gas production operation in the laboratory.
(2) To improve students' ability to analyze and solve practical problems by studying the preparation method of carbon dioxide in the laboratory; Through experiments, students' observation ability, experimental ability and initiative to acquire knowledge are cultivated, and their awareness of participation, cooperation and exploration is continuously enhanced.
2, process and method:
Through the process of divergence and convergence of thinking, the exploration process of drug selection for carbon dioxide production in the laboratory is completed. Two exploratory experiments were completed by using the learning process of combining group experiments with demonstration experiments. Through the link of the designed device, the understanding and knowledge of the device can be improved.
3. Emotional attitudes and values
(1) Cultivate students' scientific quality of being realistic, innovative and cooperative through experiments and problem discussion.
(2) Through cooperative study and research study between teachers and students, students can experience the fun of successful inquiry, stimulate students' curiosity and form a sustained interest in learning chemistry.
Fourth, teaching methods and teaching design ideas
1. Teaching methods:
The teaching method of combining activity inquiry, cooperation and exchange, discussion and induction.
2. Instructional design concept:
The teaching of this course focuses on students' participation, because students' active learning is the best way to acquire knowledge and skills. In addition, a number of inquiry links are set up in the teaching process, which naturally runs through the whole classroom teaching, keeping students' learning enthusiasm and experimental ability well. Another breakthrough is to achieve instant feedback through various means.
Teaching is divided into three parts: introducing new lessons, teaching new lessons, reflecting and upgrading, and assigning homework.
1) Introduce new courses. On-site introduction, an accident occurred when handling marble products. What gas was produced in the accident? Students complete the first inquiry process by guessing, verifying and drawing conclusions. Then think about it, what is the use value of this experiment? So as to introduce today's teaching content. Then write down the teaching objectives of this section on the blackboard, introduce the important and difficult points, and wait for the students to complete all parts of the blackboard.
2) Teaching new lessons. In the process of making carbon dioxide drugs in the laboratory, I adopted the thinking training mode of letting students diverge first and then converge. Let them choose the method to obtain carbon dioxide from the existing knowledge, and then choose the most suitable method to make carbon dioxide in the laboratory through heated discussion. Next, through grouping experiments, select the most suitable one from several similar drugs. Then the students finish writing on the blackboard to realize immediate feedback and correction. Because students have not learned the double decomposition reaction, they teach it directly in the teaching without too much development, which makes the teaching focus prominent. But I try to teach the law of reaction to exchange ideas and let students understand and master equations. In the process of gas production, this part of knowledge is relatively basic because of the knowledge reserve of oxygen production. After simply reviewing the oxygen gas preparation device, students are not required to review the knowledge of carbon dioxide, so that they can refine their own knowledge points and choose their own designs, and then show their own designs through video projection, which is convenient for finding problems and achieving the purpose of timely feedback again. Next, the teaching enters the demonstration stage, requiring student representatives to complete the operation of gas making and gas testing to test their gas making skills. Then, through the students' evaluation of their own experimental process problems, they can correct their mistakes in time and realize the participation of multi-level students.
3) Classroom reflection
The teacher asked: the reaction of the above experimental devices has not stopped. What do you think of this? How to solve this problem? Invite students to participate in the discussion, analyze the reasons, make plans and solve problems, so as to improve their knowledge, improve their experimental analysis ability and guide them to form a study habit of being good at reflecting on experiments.
4) Transfer
Auxiliary handout.
Preparation of teaching AIDS for intransitive verbs;
Instruments: conical flask, flat-bottomed flask, beaker, test tube, gas container, long-necked funnel, airway (curved or straight), alcohol lamp, iron frame, matches, small blackboard.
Medicine: marble block, sodium carbonate powder, dilute hydrochloric acid, dilute sulfuric acid, lime water.
VII. Teaching process
Create teaching situations, organize discussions, and determine the reaction principle and reaction drugs for preparing carbon dioxide? Recall the methods and devices for making oxygen in the laboratory, and determine the devices for making carbon dioxide in the laboratory. ? Show the relevant instruments for preparing carbon dioxide, and let students design and complete the preparation of carbon dioxide. ? Summarize and practice in class. ? Assign homework.
Eight, blackboard design
How to make carbon dioxide in the laboratory
(A) drugs and reaction principle
Medicine: limestone (or marble) and dilute hydrochloric acid.
Principle: CaCO3+2hcl = = CaCl2+H2O+CO2?
(2) Determination of equipment
Generation device:
Collection equipment:
(3) making carbon dioxide in the laboratory
Generator: solid+liquid? gas
Collection device: upward exhaust mode.
Full inspection: put the burning wooden stick at the mouth of the gas container, and it will be full when it is extinguished.
Inspection: Pour in clear lime water, and when it becomes turbid by oscillation, it will be carbon dioxide.
Making a lecture on carbon dioxide in junior middle school chemistry laboratory (2) I will analyze today's topic from the following aspects: teaching material analysis, teaching method analysis, learning method guidance and teaching process analysis. First of all, let me talk about teaching material analysis:
First, the status and role of teaching materials
This unit is the most complete knowledge system of learning elements and compounds in junior middle school chemistry, and carbon dioxide is a very important content of this unit. The study of carbon dioxide production plays a very important role in this book and even in the whole junior middle school chemistry learning process. The best example is to cultivate students' thinking about drug selection, device design and experimental methods when preparing a certain gas in the laboratory. Doing this lesson well will have a great influence on students' learning knowledge of elements and compounds in the future and improving their basic operation ability and experimental inquiry ability in chemical experiments. Students have learned the laboratory preparation method of oxygen, and have some practical experience in gas preparation, and various experimental techniques are also preliminarily available. This time is a good opportunity to reflect students' dominant position in classroom teaching and really let students participate in the teaching process. According to the new curriculum standards and the cognitive characteristics of junior three students, combined with the syllabus, the teaching objectives of this course are as follows:
Second, the teaching objectives
1, knowledge and skills
(1) Understand the commonly used reagents and methods for preparing carbon dioxide in the laboratory;
(2) Learn to make and collect carbon dioxide in the laboratory;
(3) Master the method of measuring carbon dioxide;
(4) Practice basic experimental operations such as taking medicine, checking the air tightness of the device, and collecting gas by exhaust method.
2. Process and method
(1) Understand the method and significance of scientific inquiry through the whole inquiry process;
(2) After participating in scientific inquiry activities, a simple inquiry plan and experimental scheme will be drawn up;
(3) The experimental device can be designed independently by using the existing instruments flexibly;
(4) Let students experience and reflect in the process of experimental inquiry, be familiar with basic experimental skills, and cultivate the ability of observing and analyzing problems from multiple angles and levels.
3. Emotional attitudes and values
(1) Cultivate students' independent, realistic, cooperative and innovative learning quality through experimental inquiry;
(2) Experience the fun of scientific inquiry and stimulate the interest in learning chemistry through the final successful manipulation experiment.
(3) Through teachers' guidance and students' independent operation, students' happiness can be increased and a good and harmonious relationship between teachers and students can be established. Chemistry is a subject based on experiments, and many basic theories, basic concepts, properties of substances and preparation methods are based on experiments.
Third, the focus and difficulty of teaching
1, teaching emphasis: students can successfully complete a series of inquiry experiments.
2. Difficulties in teaching: Through the induction and summary of exploratory experiments, correctly select the drugs, reaction principles and experimental devices for preparing carbon dioxide in the laboratory.
Of course, in the process of students' inquiry, teachers' timely questioning, proper guidance and proper guidance are the key points for the success of this class.
Take students as the center, give full play to students' autonomous learning ability and innovative spirit, and mobilize students' learning enthusiasm. This is the teaching purpose and teaching method advocated by constructivism teaching. It is around this leading idea that I will mainly adopt the following teaching methods in this class to highlight key points and break through difficulties.
Fourth, the analysis of teaching methods
1, inquiry experimental teaching method:
Teachers ask questions according to the objectives, guide students to do experiments and experience the process of experiments. A teaching method that teaches students to draw scientific conclusions through experiments, observations and explorations.
2. Interactive teaching method:
In the process of teacher's explanation, students guess, discuss and answer first. In the process of students' experiments, teachers guide and answer questions, and teachers and students constantly exchange information, which helps students to concentrate and improve their learning enthusiasm.
3. Competition teaching method:
According to the characteristics of junior middle school students' strong sense of collective honor and competitive spirit, the method of group competition is adopted, in which students can improve.
The enthusiasm of high school students' independent participation is conducive to the consolidation and application of knowledge.
Through the use of the above teaching methods, fully reflect? Teachers as the leading factor and students as the main body? Teaching principles of.
V. Guidance on learning methods
1, inquiry learning:
Students explore why carbon dioxide can't be prepared by other drugs in the laboratory through experiments. By learning the generator and selecting other instruments to prepare carbon dioxide, students' observation ability, language expression ability and analysis ability are cultivated, and the spirit of pioneering and innovation is cultivated.
2, autonomous learning:
Instruct students to complete the inquiry experiment independently. Summarize: Why can't dilute sulfuric acid and concentrated hydrochloric acid replace dilute hydrochloric acid? Sodium carbonate can't replace marble? Wait a minute. So as to arouse the enthusiasm of students' thinking and make them acquire knowledge independently.
3. Cooperative learning:
Using group experiments and group discussions, students can innovate in communication, develop in communication and acquire new knowledge in cooperation.
4, inductive learning:
Summarizing while recording experiments can promote the development of thinking and improve the ability of analyzing and solving problems. Let me talk about the teaching process, in which I will ask questions? Analyze the problem? Conduct experiments? Analysis and conclusion? The main line of applying the conclusion is divided into five steps:
Sixth, the teaching process.
1, suspense
Aristotle, an ancient Greek educator, famously said: Thinking begins with surprise and doubt. ?
In this lesson, I first told my classmates two short stories: A long time ago, in a state in West Germany, there was a strange land: whenever a hunter led a dog by, the hunter was safe, but the dog died. At that time, people there said that there was a devil in this land, and he liked eating dogs best. There is a famous dog killing cave in the mountainous area of Naples, Italy. It is said that there is a dog slayer in the cave. People entered the cave unharmed, but the dog died.
The suspenseful color in these two storylines gripped the students tightly, and then asked: Do you know what this monster is? Do you want to catch this monster?
This leads to the topic. Study on preparation of carbon dioxide.
2. Warm up
A set of information about making oxygen in the laboratory was presented in the class:
Three methods and two sets of devices; Inspection, overall inspection, inspection and collection are all reviews, which guide students to obtain relevant information about carbon dioxide according to their own life experience and existing facts, and make knowledge preparation for exploring the preparation of carbon dioxide in the laboratory.
This link is actually a link to ask questions and analyze problems. After reviewing the data of oxygen production, ask questions about the methods and equipment of carbon dioxide production and the methods of inspection, filling, testing and collection, so that students can make analogy analysis and lay a good foundation for future exploration.
3. Experience
Content 1: Explore the ideal raw materials for preparing carbon dioxide.
I gave some drugs and test tubes such as concentrated hydrochloric acid, dilute hydrochloric acid, dilute sulfuric acid, sodium carbonate and calcium carbonate, and suggested that students choose raw materials from the aspects of low price, moderate reaction speed, easy collection, pure gas and simple operation, and then let students operate, discuss and explore in groups to find their ideal raw materials. This design not only allows students to experience the scientific inquiry method of comparative observation, but also pays attention to students' experiential learning to acquire new knowledge. After finding the ideal raw materials, we should choose the right equipment. (
Lecture notes on carbon dioxide generation research (2)
Content 2: Explore the experimental device for producing carbon dioxide.
(1) Given instruments, students design their own experimental devices.
I use slides to project several sets of commonly used devices for preparing carbon dioxide, so that students can review the experimental devices for preparing oxygen with hydrogen peroxide, and then design the devices for preparing carbon dioxide according to the specified chart. And carry out encryption, full inspection, inspection and collection operations. Then discuss in groups and learn interactively, and summarize and evaluate the advantages and disadvantages of their respective equipment and the problems existing in operation. This process makes students have a certain understanding of the experimental operation and the choice of instruments, and creates a good foundation for the subsequent self-selected instrument assembly experiments.
(2) Self-selected instruments and self-designed new schemes.
On the basis of the previous exploration, let students choose their own musical instruments from the musical instrument library, and give full play to their imagination and creativity by consulting books and materials, encourage them to design more programs, and let them become the masters of the classroom and freely express themselves incisively and vividly. This link can give full play to students' subjective initiative and cultivate a strong interest in learning.
(3) Show and share:
Let each group of students show their own design scheme, and let each group of students exchange their own experimental conditions, analyze the reasons for the success or failure of the experiment, reflect on the defects of the group design, and finally choose the best design. The designer will speak and share the design results with you, so that students can exchange the goods they need, stimulate resonance and improve together.
Very few students choose single-hole plugs, most students choose long-necked funnel double-hole plugs, and quite a few students choose perforated plastic plates and spring clips.
(4) Summary
When the classroom atmosphere is high, ask questions in time: What aspects should be considered in the selection of instruments for carbon dioxide experimental preparation? (for example, the state of reactants and reaction conditions should be considered from a big perspective. In details, we should consider saving drugs and controlling reactions. ) so as to guide students to return to the theme and summarize, condense and sublimate the little gains in the process of inquiry in time.
I mentioned the main line just now. Suspense and review reflect questions and doubts, while experience reflects experiments and analysis to draw conclusions. Let me talk about the application conclusion.
Step 4 harvest
Please use the most suitable drugs and ideal devices to generate carbon dioxide and collect it in the most reasonable and fastest way.
Setup, inspection and testing. Because of the previous inquiry, the students quickly completed the assignment. At this time, I gave a positive evaluation in time, praised their good qualities of serious participation, bold operation and active exploration, encouraged them to make persistent efforts and create new achievements, so that students can climb higher and go further with encouragement.
Step 5 extend
(1), looking for some experimental substitutes from real life, designing a device to make carbon dioxide, completing a small family experiment to make carbon dioxide, and improving students' ability to integrate theory with practice.
(2) Through the analogy of oxygen and carbon dioxide produced in the laboratory, students can discover the law and guide them to explore the preparation of other gases, so as to exercise students' ability to draw inferences about knowledge, make students think differently and enhance their grasp of the connection and transmission of knowledge.
Seven, blackboard design
Study on preparation of carbon dioxide
I. Drugs and reaction principles
1. medicine: marble or limestone and dilute hydrochloric acid.
2. Principle: CaCO3+2HCl=CaCl2+H2O+CO2?
Second, the determination of device
1. Generator: solid and liquid unheated type.
2. Collection device: upward exhaust mode.
Third, inspection and full inspection.
1. Inspection: Pour clear limewater, and when it becomes turbid by shaking, it becomes carbon dioxide.
2. Full inspection: put a burning wooden stick at the mouth of the gas container, and it will be full after being extinguished.
Four. Extension:
Laboratory gas preparation
Raw materials: low price, moderate speed, easy collection, pure gas and simple operation.
Device: It depends on the state of reactants and reaction conditions.
Hierarchical exercise: let students at all levels get exercise and promotion.
I will talk about it all the time in today's class. Integral? Real? Integral? According to this main line of inquiry, we should focus on the harmonious unity of teachers' leading role and students' main activities, the harmonious unity of teaching methods and learning methods, the harmonious unity of imparting knowledge and intelligent development, and the harmonious unity of moral education and intellectual education.
Making lecture notes on carbon dioxide in junior middle school chemistry laboratory (3) Dear leaders and teachers, good afternoon! I'm Luo Weidong from Laojuntai Middle School. I said the topic of the class was "Study on Laboratory Preparation of Carbon Dioxide", the second section of Chapter 5 of Grade 9 Chemistry of Guangdong Education Press.
Preparation before class
1. Analysis of learning situation
Junior high school students are curious, eager for knowledge and expression, and like to use their hands and brains. Their way of thinking is changing from perceptual thinking to logical thinking, and they already have certain ability to analyze and solve problems. According to this characteristic of students, I will mainly use self-study guidance and learning plan guidance in this class. Although students usually have few opportunities to do experiments, I believe that through experiments and multimedia teaching, students can completely complete this course.
2. teaching material analysis
This course is not only a review and consolidation of the preparation methods of oxygen laboratory, but also the best material to train students to consider how to choose drugs, design generating devices and collect common gases when preparing a certain gas in the laboratory.
3. Teaching objectives
(1) Knowledge and skill objectives
① Understand the reaction principle of producing carbon dioxide in the laboratory, and explore the generating device and collection method of carbon dioxide.
(2) Master the methods and design ideas of gas production in the laboratory.
(2) process and method objectives
① By exploring the methods and design ideas of making gas in the laboratory, students can learn the basic process and methods of scientific inquiry and experience the scientificity of chemical experiment methods.
② Let students carry out preliminary scientific inquiry activities.
(3) Emotional attitude and values goals
① Cultivate students' qualities of seeking truth from facts, innovative spirit and scientific cooperation through experimental inquiry activities. ② Cultivate students' interest in participating in chemical experiments, improve their self-confidence and stimulate their enthusiasm for learning through practical inquiry activities.
4. Emphasis and difficulty in teaching
Key points: ① Explore the reaction principle of carbon dioxide generation in the laboratory.
② Explore the generating device and collection method of carbon dioxide produced in the laboratory.
Difficulties: Explore the design ideas and methods of laboratory gasification.
5. Teaching equipment
The big screen shows the teaching equipment to be used in this class, adding some chemical instruments and drugs that are not involved in the textbook. It is hoped that through the comparative experiments between the four groups, students will have a deeper understanding of the drug choice in this class.
teaching program
The teaching process of this course is divided into four teaching links:
1. Self-study and discussion stage
First of all, the gas produced by the oscillation of cola drinks can make the clarified limewater turbid and introduce it into the new lesson?
Then explain the teaching objectives, and then I put forward the general self-study outline of this class: what are the methods and design ideas of laboratory gas production? Let the students learn the text by themselves and complete the "Part I Basic Self-study Problem" under the guidance of the study plan.
After about 8 minutes, I asked the students to discuss and summarize themselves. Through the selection and comparison of oxygen generation device and collection method, I basically determined the generation device of carbon dioxide laboratory method in this course.
2. Experimental discussion stage
This stage is the core part of the teaching process, and the time is about 10 minute.
First of all, the teacher made a demonstration experiment with a simple device, made a bottle of carbon dioxide, and checked the filling, so that students could basically master the experimental steps.
Next, the teacher organized students to explore experiments in groups: the first group reacted with concentrated hydrochloric acid and limestone; The second group reacts with dilute hydrochloric acid and limestone; The third group reacts with dilute sulfuric acid and limestone; The fourth group reacts with sodium carbonate powder and dilute hydrochloric acid; Students in each group are required to observe the experimental phenomena carefully, and the group leader should make a record of the experimental phenomena.
Teachers should patrol and guide in the experiment, correct the mistakes in students' operation in time, and remind students to observe the experimental phenomena at any time.
Through experimental discussion activities, students can personally experience that making carbon dioxide is not an easy task, which generally requires six steps, and the choice of raw materials is scientific, not random. This also fully highlights the students' dominant position and cultivates their scientific inquiry ability, thus achieving the first breakthrough in the teaching focus of this class.
3. Discussion stage of solving doubts
This stage is a further deepening process of the experimental discussion stage, which is divided into four inquiry activities, and takes about 10 minutes.
Students are divided into groups for about 10 minutes, then the teacher organizes four groups to report the experimental phenomena one by one, and then let the students think independently according to the part of the study plan (the second part of the difficult problem) before discussing (projecting): (1) Can concentrated hydrochloric acid and marble react?
(2) Is it ok to react with marble with dilute sulfuric acid? (3) Can dilute hydrochloric acid react with sodium carbonate? On the basis of students' discussion, teachers participate in students' discussion, give timely guidance, help students solve problems, fill in the experimental report carefully, and determine to prepare carbon dioxide from dilute hydrochloric acid and limestone.
On the basis of determining the raw materials for preparing carbon dioxide, organize students to look at the projection and design generators for preparing carbon dioxide in groups. On the basis of learning from others, four groups were asked to make a simple generator with needles, droppers, droppers and beverage bottles prepared in advance. Finally, the teacher organized students to report the experimental process in groups, and one student in each group explained and showed the production results.
Next, organize students to explore the carbon dioxide collection device made in the laboratory according to the density and water solubility of gas. Finally, according to the nature of the substance, the method of carbon dioxide inspection and total inspection is determined.
In this independent inquiry learning activity, every step highlights the students' dominant position and guides them to try to acquire scientific knowledge by low-cost methods, thus deepening the second breakthrough of the teaching focus of this class.
4. Comprehensive discussion stage
This stage is also the summary stage, which takes about 10 minutes.
First, organize students to review and summarize, so that students can systematically master what they have learned.
Next, I organize students to solve the "third part comprehensive discussion" with the learning plan as the guide. I have designed two questions, (1). What is the basis for the laboratory to choose the gas generator? (2) What is the basis for the laboratory to choose the gas collection method? This is also the self-study outline I put forward in the self-study stage (what are the methods and design ideas of laboratory gas production? ) Step-by-step solutions to teaching difficulties will enable students to rise from perceptual knowledge to rational knowledge. At this point, this lesson is echoed from beginning to end, the teaching emphases and difficulties have been solved, and the students' experimental inquiry ability and innovative quality have been further cultivated.
The blackboard design takes about 5 minutes.
Extended application
Have you ever eaten vinegar eggs (preserved or soft eggs)? Will you detect that the main component of eggshells is carbonate? Please use the knowledge in this section to write an inquiry report to test the main components of egg shells.
Teaching reflection
First, the realization of three-dimensional goals
Second, the improvement of experimental equipment.