Teaching Design of Chemistry for Senior One in People's Education Press (1)
Introduction of New Lessons [News Guide] Ammonia leakage occurred in a refrigeration workshop in Hangzhou;
On the morning of April 20th, 2004 10, ammonia gas leaked from a refrigeration workshop in Hangzhou. The whole factory is white, hundreds of meters away from Fiona Fang, and there is a strong pungent smell in the air, which makes it difficult for people to breathe in the factory. It's cold in the factory. After receiving the report, the municipal fire center immediately made plans to send hundreds of firefighters and ten standby fire engines.
[question]
1. Why is it cold in the factory when ammonia leaks?
2. How to absorb a large amount of ammonia in the air?
3. What can people trapped in polluted areas do to ensure that they will not inhale ammonia?
[blackboard writing] ammonia
1 and the physical properties of NH3:
[Description] A bottle of ammonia: colorless, irritating, dense in air and easy to liquefy, can be used as a refrigerant.
[Experiment 4-9] The key to success: the flask is dry and sealed.
Phenomenon: forming a red fountain. It is proved that ammonia is soluble in water and the aqueous solution is alkaline.
[Explanation] 1 volume of water dissolves about 700 volumes of ammonia, and the aqueous solution of ammonia is called ammonia water.
[Blackboard] Under normal circumstances, ammonia is a colorless gas with an irritating smell, which is lighter than air. Ammonia is easily liquefied and soluble in water.
[Transition] The aqueous solution of ammonia is alkaline, but the water in it is neutral, and ammonia molecules have no hydroxyl ions. Why is ammonia alkaline?
[blackboard writing] 2. Chemical properties of ammonia:
(1) The reaction of NH3 with water;
[analysis]
Among them, ammonia monohydrate is very unstable and will decompose NH3·H2O = = NH3 =+H2O when heated.
[Blackboard] NH3+H2O = = NH3 H2O = = NH4++OH-
[Thinking]: Analyze the process of NH3 dissolving in water, and discuss the components in ammonia water: molecules and ions.
[Blackboard] (Reaction of NH3 with Acid:
[Demonstration Experiment] Reaction of Ammonia with Hydrogen Chloride
[Observation] Phenomenon: A lot of white smoke is produced.
[Thinking]: Chemical plants that produce Cl2 often use concentrated ammonia to check whether the production equipment and pipelines are leaking. If white smoke is produced, it means that there is air leakage. Why?
Chemical equation: NH3+HCl=NH4Cl
NH3 can also react with other acids, such as NH3+HNO3==NH4NO3, 2NH3+H2SO4==(NH4)2SO4.
[Explanation] NH3 can react with O2, NO and NO2 under certain conditions.
[Blackboard] (3) Reaction between NH3 and O2: 4NH3+5O2==4NO+6H2O
[Demonstration experiment] Preparation of ammonia gas in laboratory;
[Blackboard] 3. Laboratory preparation of NH3;
[Explanation] Principle: Ammonium salt and alkali are commonly used in the laboratory to prepare NH3. Instrument: solid+solid heating (synchronous oxygen production); Collection: exhaust method.
[blackboard writing] 2nh4cl+ca (oh) 2 = = CaCl2+2nh3 =+2h2o
Instrument: solid+solid heating (synchronous oxygen production); Collection: exhaust method.
[Question]:
1 Can NH3 be dried with concentrated sulfuric acid?
2 Can we use NH4HCO3, NH4NO3 and NH4Cl? Why?
What are the advantages of using alkali lime instead of hydrated lime?
[Transition] Ammonia reacts with acid to form ammonium salt. Let's analyze the properties of ammonium salt.
[blackboard writing] 4, ammonia salt
[Narrator] Ammonium salt is a compound composed of ammonium ion (NH4+) and acid ion. Ammonium salts are all crystals and can be dissolved in water.
Main chemical properties:
[blackboard writing] (1) ammonium salt is easy to decompose when heated;
[Experiment] Heating NH4Cl to observe the phenomenon, is it sublimated?
[Blackboard] Chemical equation: NH4Cl = = NH3 =+HCl =, NH3+HCl=NH4Cl.
NH4HCO3==NH3↑+H2O+CO2↑
[Explanation] Ammonium salts can react with alkali to release ammonia gas, for example, (NH4) 2SO4+2NaOH = = Na2SO4+2NH3 ↑+2H2O.
[Blackboard] (2) Reaction between ammonium salt and alkali: (NH4)2SO4+2NaOH? ==Na2SO4+2NH3↑+2H2O
[Key] This property is the isomorphism of all ammonium salts, which can be used to test the existence of NH4+ in the laboratory.
[Note]: Experimental conditions: concentrated solution or solid, heated.
Test method of ammonium ion in dilute solution: first concentrate, then test.
[Blackboard] 5. Use of NH3:
【 Description 】 It can be used as refrigerant in nitrogen fertilizer industry and other chemical industries (such as soda production).
[Thinking and communication] Nitrogen cycle in nature;
Summary after class
Teaching Design of Chemistry for Senior One in People's Education Press (2)
First, the analysis of learning objectives
(A) the basis for determining the learning objectives
Compulsory module requirements and elective module requirements
Curriculum standards require module learning requirements, and curriculum standards require module learning requirements.
Important applications of alloy materials can be listed.
1, the important applications of aluminum alloy materials in production and life can be listed.
2. Understand the application of copper alloys in industrial production and high-tech fields.
Understand the main differences between metals and alloys in performance, and understand the composition of common alloys in life.
1. Understand the main differences between metals and alloys in performance.
2. Understand the composition of common alloys in life.
learning target
1. Knowledge and skills objectives
(1) The important applications of ferroalloy materials in production and life can be listed.
(2) Understand the application of copper alloys in industrial production and high-tech fields.
2. Process and method objectives
(1) Use alloy materials in life to create learning situations and guide students to learn independently.
(2) Classify and summarize the teaching materials and alloy information given by teachers to guide students to process information.
(3) Experience the process of interaction between scientific knowledge and social life.
(4) Experience the process of scientific research and collecting and sorting out information by completing small papers.
3. Emotional attitudes and values goals
(1) Encourage students to ask questions actively through various activities, and cultivate the spirit of questioning and innovation. Through mutual communication and role-playing activities, we can enhance our feelings and cultivate the spirit of cooperation.
(2) Through the application examples of metal materials in production and life, improve students' enthusiasm and curiosity in learning chemical knowledge, and stimulate students' patriotic enthusiasm and sense of responsibility and mission in serving the society.
Second, the analysis of teaching difficulties
The history of material development reflects the civilization degree of human social development from the perspective of productivity. In view of the fact that metal materials play an important role in a country's national economy and are widely used in daily life, this section mainly studies the properties of alloys, the components and important uses of commonly used alloys, and how to choose metal materials correctly. In addition, the metal material itself is still developing, and new technologies are constantly emerging in the traditional steel industry in terms of smelting, casting, processing and heat treatment. New metal materials such as superalloys, shape memory alloys, hydrogen storage alloys, permanent magnet alloys and amorphous alloys have come out one after another, greatly expanding the application scope of metal materials. Therefore, the challenges faced by introducing metal materials can stimulate students' sense of social responsibility.
Based on the above viewpoints, the teaching priorities are established as follows:
(1) The main components and properties of ferroalloys and copper alloys in life are the focus of this section;
(2) Cultivating students' ability to acquire and organize information and improving students' practical ability is the focus of teaching;
(3) How to mobilize students' active participation and autonomous learning is the focus of teaching.
The difficulty lies in:
Mobilize students' active participation and autonomous learning.
Third, the arrangement of teaching content.
(A) the content of this section in the status of teaching materials
The content of this section is to further deepen and improve the metal and metal materials introduced in junior high school. Choosing "sodium, aluminum, iron and copper" as the metal type is representative: except sodium, the other three metals are common metals, and students have perceptual knowledge and can combine the application of metals in daily life. In view of the important position of metal materials in the national economy and their wide application in daily life, the section of metal materials is compiled to reflect the times of teaching materials and the connection between teaching and production and life practice.
(B) Analysis of teaching content
This course is the teaching content of the third section of Chapter 3 of Chemistry 1 published by People's Education Publishing House. It is the application of metal knowledge and is closely related to the actual production and life. Teaching is divided into two parts:
The first part: Let students form a preliminary concept of metal materials, and then learn through objects, pictures and videos.
Properties of alloys, compositions of common alloys and important uses.
The second part: Through the study of metal materials and related knowledge, let students understand the significance of rational use of metal materials.
Justice.
Contents of Alloy and Metal Materials Students have a certain knowledge base in Grade Three. The curriculum standard only requires "listing the important applications of ferroalloy materials in production and life, and understanding the application of copper alloys in industrial production and high-tech fields", and should not introduce the composition, properties and uses of various alloy materials too much, resulting in excessive use of classroom resources. It is necessary to focus on practical activities (small papers should be extended to extracurricular activities, so that they can be well mobilized and guided) and organize discussions on material selection. These teaching contents fully reflect the teaching objectives of process, method, emotion, attitude and values, and deserve corresponding attention and teaching resources.
(3) Class schedule: 1 class.
Four. Suggestions on teaching resources
(1) A large number of pictures and video materials are used in the teaching of various metal materials, and common metal materials such as iron and copper can be displayed in kind to enhance students' perceptual knowledge; Show pictures or videos of various metal materials to help students deepen their understanding of metal materials such as alloys.
(B) citing a large number of examples in life
(3) Make full use of relevant websites.
Verb (abbreviation of verb) teaching methods and learning guidance strategies
This course does not require high knowledge and skills, and the focus of teaching is how to implement "process and method" with knowledge as the carrier in classroom teaching and realize "emotional attitude and values".
In the process of teaching, it is suggested to use a variety of learning methods flexibly, organically combine teaching and learning, and organize diversified learning activities.
1. Think independently
Exchange discussion
Show communication
4. Student summary
Suggestions of intransitive verbs on teaching resources
(A) Internet access to the history of the development of materials science in China
(2) You can consult relevant information on the Internet to discuss whether you should stop using aluminum beverage cans.
(3) Choose any topic about alloys that you are interested in to investigate and complete a short essay about alloys.