Part II: Structural characteristics of organic compounds. Focusing on the bonding characteristics and bonding modes of the core atoms of organic compounds, the isomerism phenomenon is systematically introduced layer by layer, so that students can understand why there are so many kinds of organic compounds. This section studies carbon chain isomerization, positional isomerization and functional group isomerization. Starting from reviewing the carbon chain isomerization of alkanes, the carbon chain isomerization of olefins and the position isomerization of functional groups (carbon-carbon double bonds) are derived, and the significance of functional group isomerization is illustrated by taking ethanol and dimethyl ether as examples. This reveals that isomerism is caused by different bonding modes of atoms in organic compounds, which is one of the reasons for the large number of organic compounds. There is room for future study, that is, although the molecular formula is the same, the chemical properties of organic compounds are different due to different connection methods (different structures), so the uses of these organic compounds in people's daily production and life are also different, thus reflecting the basic methods of compound learning in chemistry: structure determines properties and properties determine uses.

frame of reference

Chemistry curriculum standard

Teaching guidance and module learning requirements

(Chemistry 2 Topic 1: Material Structure Basis)

1, to understand the bonding characteristics of carbon in organic matter.

2. Illustrate the isomerism of organic compounds with examples.

(Chemistry 2 Theme 3: Chemistry and Sustainable Development)

Understand the molecular structure of methane, ethylene and benzene.

(Basic Course of Organic Chemistry 1: Composition and Structure of Organic Compounds)

1, know the structure of common compounds, understand the functional groups in organic molecules, and correctly express their structures.

2. Through the analysis of typical examples, it is known that there is isomerism in organic compounds, and the isomerism of simple organic compounds can be judged.

(Compulsory 2)

1, to understand the bonding characteristics of organic compounds (taking methane, ethylene, etc. as examples. For example, understand the bonding characteristics between carbon atoms in organic compounds)

2. Explain the isomerism of organic compounds.

3. Understand the molecular structure of methane, ethylene and benzene.

4, know the molecular structure of ethanol, know the molecular structure of acetic acid

(optional 5)

1, know the structure of common organic compounds, understand the functional groups in organic molecules, and correctly express their structures (know the bonding mode and characteristics of carbon atoms in common organic compounds, know the main functional groups in organic compounds and their structural characteristics)

2. Through the analysis of typical examples, we can know the isomerism of organic compounds and judge the isomerism of simple organic compounds (through the analysis of typical examples, we can know the isomerism of organic compounds, which is one of the reasons for the variety of organic compounds. The types of isomers of simple organic compounds can be determined according to their structures)

Comparison between compulsory and compulsory knowledge points of organic compounds

need

Choose positively

Knowledge point comparison

1, to understand the bonding characteristics of organic compounds (taking methane, ethylene, etc. as examples. For example, understand the bonding characteristics between carbon atoms in organic compounds)

2. Explain the isomerism of organic compounds.

3. Understand the molecular structure of methane, ethylene and benzene.

4, know the molecular structure of ethanol, know the molecular structure of acetic acid

1, know the structure of common organic compounds, understand the functional groups in organic molecules, and correctly express their structures (know the bonding mode and characteristics of carbon atoms in common organic compounds, know the main functional groups in organic compounds and their structural characteristics)

2. Through the analysis of typical examples, we can know the isomerism of organic compounds and judge the isomerism of simple organic compounds (through the analysis of typical examples, we can know the isomerism of organic compounds, which is one of the reasons for the variety of organic compounds. The types of isomers of simple organic compounds can be determined according to their structures)

1, knowledge and skills:

(1) Further understand the bonding characteristics of carbon atoms in organic compounds and understand the reasons for the variety of organic compounds.

⑵ Through the analysis of typical examples, it is known that there are isomerism (carbon chain isomerism, positional isomerism and functional group isomerism) in organic compounds, and the structural formula of simple alkane isomers can be preliminarily written.

2, process and method:

⑴ Make a model, so that students can get personal experience in practice and understand the meaning of "model method" initially.

⑵ In the process of learning isomerism, we realize that the diversity of material structure determines the diversity of material properties.

3. Emotions, attitudes and values

(1) Cultivate students' awareness of active participation.

⑵ Through the writing of isomers, the order and rigor of students' thinking are cultivated.

⑶ The determination process of carbon valence tetrahedron theory encourages students to explore the essential characteristics of problems and experience the process of scientific research.

Second, the teaching content arrangement

Students have mastered the structures of methane, ethylene and benzene in their previous studies. It can be said that students have the foundation to study the structural characteristics of each kind of organic matter, and then lay the foundation for learning the general steps and methods of studying organic matter. Comparing the required knowledge with the required knowledge, it is not difficult to find that the required knowledge starts from the carbon chain isomerization of alkanes and extends to the carbon chain isomerization of olefins and the position isomerization of functional groups (carbon-carbon double bonds). Students have studied organic compounds such as methane and ethylene in compulsory courses, and have a preliminary understanding of the influence of molecular structure of organic compounds on their properties, but at this time, students' understanding of organic compounds is scattered, and it is necessary to systematize the scattered knowledge. Although students know the general situation of organic compounds, they know that carbon atoms in organic molecules are tetravalent, and carbon atoms can form valence bonds with other atoms and can form bonds with each other; Carbon atoms can form carbon-carbon single bonds, carbon-carbon double bonds, carbon-carbon triple bonds and so on. Organic substances can form chain molecules or cyclic molecules. However, it is necessary to deepen the bonding characteristics of carbon atoms and the combination mode between carbon atoms, and deepen the understanding of concepts such as saturated hydrocarbon, unsaturated hydrocarbon, alkane and olefin. Therefore, we can further understand the bonding characteristics and isomerization phenomena of organic compounds-carbon chain isomerization, positional isomerization and functional group isomerization. Make students' cognition gradually develop from perceptual thinking to rational thinking.

Third, the analysis of teaching difficulties

Students learned some typical organic compounds, such as methane, ethylene, benzene, ethanol, acetic acid, sugar, oil, protein and so on, and learned their main properties. But now students' knowledge of organic matter is scattered and not systematic enough. Although students understand the general situation of organic compounds and know that carbon atoms in organic molecules are tetravalent, and carbon atoms can bond with other atoms or with each other, they still need to deepen their understanding of the bonding characteristics and bonding methods of carbon atoms. The connection between carbon atoms and other atoms is different, which leads to a wide variety of organic substances. The bonding mode of carbon and the writing of alkane isomerization are very important contents in organic chemistry learning. After that, functional group isomerization, cis-trans isomerization and other contents are based on him. Based on the above analysis, the teaching emphases and difficulties in this section are determined as follows:

The teaching emphasis of this section: 1. Bonding modes of carbon atoms in organic compounds.

2. Isomerism and Isomerism

Teaching difficulties in this section: 1. Writing of alkane isomers (carbon chain isomerization)

Four. Suggestions on teaching resources

(A) make full use of the model method to effectively combine teaching resources.

For example, in the teaching of isomers, students can use the model or plasticine to build their own club model of organic compounds, discuss the structure of dichloromethane, and clarify the significance of the construction of three-dimensional model of organic compounds to organic chemistry. When introducing the sp3 hybrid orbital model of carbon atoms, teachers should provide model teaching AIDS to enhance students' perceptual knowledge of microstructure, and also use multimedia to demonstrate the formation process of different structural isomers of organic compounds and the real structures of different isomers.

(B) make full use of the columns in the textbook

For example, introducing the history of science into this section can effectively help students build a three-dimensional model of organic structure and explain its essential reasons. It is suggested that it be regarded as a tool, and no further requirements are required.

(C) make full use of network resources

For example, we can use the campus network to put relevant learning materials on the Internet, and arrange topics for students to study independently. Relevant extended materials can be hung on the Internet to provide materials for students' further study. You can set up a class's own blog, where you can exchange students' own learning experiences and get mutual help. You can use the internet to find relevant teaching materials and extended materials, such as k 12, Chemical Resources Network, New Thinking Network, People's Education Network, Central Audio-visual Education Center, etc.

(D) to strengthen the division of labor and cooperation among students.

Verb (abbreviation of verb) Suggestions on teaching methods and learning guidance strategies

1. Students' homework before class: Summarize the molecular formula, structural formula, simplified structure and spatial configuration of methane, ethylene and benzene, and complete the spatial model of methane, ethylene and benzene in groups at the same time (students can use plasticine and toothpicks to complete it).

2. Teaching design: Bonding characteristics of carbon atoms in organic compounds. This part of knowledge can adopt experiential teaching method. Teachers and students * * * complete the study plan and show students' works about the spatial model of methane, ethylene and benzene, so that students can understand the spatial structure of organic compounds and upgrade to the carbon valence tetrahedron theory of organic compounds.

Isomerization of organic compounds. Practical teaching methods can be used for this part of knowledge. Students work in groups to complete the spatial structure of methylene chloride molecules (no isomers). On the one hand, students deepen their understanding of carbon valence tetrahedron theory; At the same time, transition to heterogeneous and heterogeneous knowledge learning. Question: Are organic compounds with the same molecular formula the same in structure? Students work in groups to complete the spatial structure of C4H 10, understand the isomerism phenomenon, and know the two isomers of C4H 10. And further implement the practice of structural formula and structure simplification of organic compounds. Through practice, the molecular structure model of C5H 12 was made, which further consolidated the concept of isomers. During the production process, the group discussed the writing method of isomer www.GeO2k.COM, focusing on how to avoid the problems of "rewriting" and "missing writing" of isomers. The representatives of the group reported the discussion results of the group, and questioned, supplemented and perfected each other among the groups, and finally worked out the writing method of alkane isomers agreed by everyone-carbon reduction process instructed students to try to write isomers of C3H6 and C2H6O. When writing isomers, we should consider three isomeric forms-carbon chain isomerism, functional group position isomerism and functional group isomerism, and master the writing method of isomers in writing practice.

3. After-class student assessment and evaluation.