The design of the "primary battery" guide case for high school chemistry under the new curriculum
[Abstract] The high school chemistry content under the new curriculum reform requires teachers and students to change the traditional teaching and learning methods. How do teachers fully inspire students' thinking in teaching, how to guide students to construct active, individualized learning, discovery-based learning, inquiry-based learning, and research-based learning proposed by the new curriculum reform? One of the keys is the design of classroom teaching. . Using the new curriculum reform concept to improve teaching design has become the focus of chemistry teaching reform.
[Keywords] new curriculum reform; chemical guidance case; design
High school chemistry new curriculum reform standard "emphasizes to enable students to form a proactive learning attitude, form correct values, pay attention to students' overall personality and individual Differences, which aim to build a classroom development based on student development, learn to think, learn to learn, and improve the overall quality of life of individuals in the process of cooperation, dialogue, inquiry and reflection. In combination with the purpose of the new curriculum reform, I attach great importance to the design of classroom teaching in the teaching. The following is the design of the guidebook for the first section of the first edition of the "Non-Battery" in the fourth edition of the high school chemistry teaching edition. I would like to share and communicate with you.
[Question] Electives, Chapter 4, Section 1, Primary Battery
Knowledge and Skills:
1. Review the composition of the original battery
2. Master the original battery Method for judging the negative electrode
3. Initially mastering the writing of the positive and negative electrode reaction type
4. Understanding the application of the principle of the primary battery
Process and method:
Through the principle of galvanic batterys, physical knowledge, Learning and
understanding of redox knowledge, cultivating students' ability to summarize and summarize.
Emotional Attitudes and Values:
Through learning, students can realize the guiding role of theoretical knowledge in solving practical problems.
[Heavy point] The method of judging the positive and negative electrodes of the primary battery; the writing of the positive and negative electrodes.
The positive and negative electrode reactions of the primary battery are written based on the redox reaction.
Self-study (10 minutes, combined with textbooks, students complete the experiment in groups and independently fill in the blanks)
First, the original battery
1. Concept: The original battery is to use _____ principle to convert _____ Device for _____ can
2. Experimental exploration (taking zinc-copper primary battery as an example, the device is shown in Figure 4-1 of the textbook, and multiple sets of experimental equipment are provided, and students are grouped to do experiments themselves)
(1) Phenomenon :1 galvanometer indicator with salt bridge _____; zinc sheet _____; copper sheet _____
2 when removing salt bridge ________________
(2) principle analysis
1 in beaker containing ZnSO4 solution In the inserted zinc sheet ____ electron, Zn is _____. The zinc sheet is _____ pole, and the electrode reaction formula is: _____
2 In the beaker containing the CuSO4 solution, Cu2+ in the solution is _____ electrons from the copper sheet, and is _____. The copper sheet is _____ pole, and the electrode reaction formula is: _____
3 salt bridge composition: _____ saturated solution; ion movement direction: Cl-shift to solution; K+ shift to _____ solution
Function: a Make two half-battery solutions ___________ b. Keep both solutions ___________.
(3) Conclusion: There is _____ in the wire, the device is a _____
Cooperative inquiry (20 minutes, combined with the textbook students to complete the discussion, and finally draw the group to write the answer on the blackboard, the group between each other Comment)
[Think 1] What are the conditions for forming a primary battery?
[Think 2] What are the methods for judging the positive and negative of the primary battery?
[Thinking 3] In chemistry learning, what are the main applications of primary batteries?
[Thinking 4] After dropping a large drop of phenolphthalein-containing brine on a piece of rust-free iron (iron-carbon alloy), the droplets gradually appear red and slowly form brown rust (main ingredient) For Fe2O3). Why is that? Explain why this phenomenon occurs? Write out the relevant electrode reaction equations and related equations.
[Typical example] (Teacher can help students with doubts)
[Example 1] In the device shown in the figure, the metality of a is stronger than that of hydrogen, and b is a carbon rod. The description is incorrect.
A. There is gas on the carbon rod, the acidity of the solution is weakened. Ba is the positive electrode, and b is the negative electrode. C. There is electron flow in the wire, and electrons flow from the a pole to the b pole. Oxidation reaction occurs on the Da pole
[Example 2] Four metal sheets a, b, c, and d are immersed in dilute sulfuric acid, and the primary batteries are connected by wires. If a and b are connected, a is the negative pole, when c and d are connected, the current is from d to c; when a and c are connected, a large number of bubbles are generated on the c pole; when b and d are connected, a large number of bubbles are generated on b, then four The order of activity of the metals from strong to weak is
Aa\u003eb\u003ec\u003ed Ba\u003ec\u003ed\u003eb Cc\u003ea\u003eb\u003ed Db\u003ed\u003ec\u003ea
10 minutes, the students complete independently, the teacher can counsel the students who have doubts, and finally the collective comment on the mistakes.
1. Design a primary battery according to the reaction principle of Zn+Cu2+=Zn2++Cu, when Zn When it is a negative electrode, the material that can be used for the positive electrode is
A. Magnesium B. Graphite C. Aluminum D. Lead
2. When working on the zinc-copper galvanic battery in the textbook, the following description is correct
A The positive electrode reaction is: Zn-2e-=Zn2+
B. The battery reaction is: Zn+Cu2+=Zn2++Cu
C. In the external circuit, electrons flow from the negative electrode to the positive electrode
D. Salt Bridge K+ shift to ZnSO4 solution
3. When the primary battery consisting of zinc, copper and dilute sulfuric acid works, the concentration of H+ in the solution changes
A. unchanged B. first becomes smaller and then becomes larger C. Gradually getting bigger D. getting smaller
4. The following figure can form the primary battery.
5. The following statements about the primary battery are correct ( )
A. The positive and negative electrodes that make up the primary battery must be two different metals
B The primary battery is a device that converts chemical energy into electrical energy. C. One pole of the electron flow is the negative electrode, and the electrode is reduced.
D. When the primary battery is discharged, the direction of the current is from the negative electrode to the positive electrode
6. The following kinds of iron plates, after the coating is destroyed, the most resistant to corrosion is _____
A. galvanized iron plate B. copper plated iron plate C. plated iron plate D. tin plated plate
7 The electrician's operating regulations stipulate that the copper wire and the aluminum wire cannot be connected together. The chemical principle is ________________
8. The main components of the "hot bag" sold on the market are iron filings, carbon powder, wood chips, and a small amount. Sodium chloride and water, etc. Before using the “hot pack”, use a plastic bag to isolate it from the air. When it is turned on, open the plastic bag and gently rub it to release heat. After use, you will find a lot of rust.
(1) "Hot pack" is to use _______ to release heat. (2) The main role of carbon powder is _____________________. (3) The main role of adding sodium chloride is _____________. (4) The role of sawdust is ________________.
After-school reflection (5 minutes, students self-summary reflection)
My gains in this lesson: ___________________________.
My doubts in this lesson: ___________________________.
 Chemistry course textbook research and development center. General high school curriculum standard experiment textbook chemical elective 4[M]. Beijing: People's Education Press, 2007
 Su Yongping. New Chemistry Teaching Design Strategy under the Background of Curriculum[J].Secondary Chemistry Teaching Reference,2010(5):15-17
Liu Zhixin.Chemical Teaching Theory[M].Beijing: Higher Education Press, 2004