It's an option 4 chemical reaction principles section 2 chemical power teaching and reflection, five pages. The curriculum includes, inter alia, a review and is open for download。
Core nucleus
Through an awareness of the chemical power sources that are common in life, students are raised with a sense of social responsibility, a sense of theoretical relevance and a sense of applying chemical results to production and life。
Guided thinking and rationale
Deepening awareness and optimizing the quality of thinking is an important goal of the choice of teaching, and its achievement should be based on the knowledge already available to the students, which is the knowledge system that must be developed. The practical situation needs to be created and, in the process of solving the problem, the students will be guided to develop their own procedures and methods。
The pedagogic design of this class is based on a comparison of the elements of “chemical power supply” between the compulsory and optional subjects, analysing the cognitive framework that students have established in the compulsory curriculum, looking for the student's “recent development zone”, and exploring and experimenting around somewhat difficult theories, helping students to develop, on the basis of the knowledge already available, an understanding of the original battery as a prototype chemical power source。
Teaching background analysis
Chemical power is not really a simple application of the original battery, but it itself reflects the scientific perspective and perspective of electrochemicals based on the original battery. This part of the chemical power supply, if only a science presentation, actually reduces the teaching value of chemical power. In particular, the chemical power source of the response principle module must be considered in isolation from the original battery. Or the original battery is the principle, and the chemical power is not the principle, but the knowledge and understanding. That's not how the original battery works. In fact, chemical power is the direct purpose of scientists studying the original battery, who produce the chemical power using the principles of the original battery, which reflects the research value of the original battery. For students, the relationship between the original battery and the chemical power source is to be established so that the chemist can learn how to study the chemical power source using the original battery. The original battery is basically the same as the chemical power source, which part has changed and what has changed between the different chemical power sources. Although students cannot carry these things behind their backs, at least students can connect in their minds, and he can understand the path and direction of scientists in developing chemical power。
The subject's goal design
3d objective: to develop an in-depth understanding of the working principles of the original battery, to clarify the internal structure and working principles of the alkaline zinc dry manganese and lead batteries, to explore experimentally the working principles of the fuel cell, to deepen the understanding of the original battery and to understand the complexity of its development into a chemical power source. Learning to write an electro-polar reaction to simple chemical power sources allows the design of simple chemical power sources based on specific oxidizing reaction. Through exploration of the difficulties that scientists have in designing chemical power sources using the principle of the original battery, chemists are exposed to the general thinking and methods of researching chemical power sources using the principle of the original battery, human thinking and confusion in the development of the use of chemical power sources, the practicality of human experience in chemical power sources to greening to sustainable cognitive development processes, and the importance of harmonious symbiotic relationships between humans and nature。
Teaching focus
Principles of operation of alkaline zinc dry manganese batteries, lead batteries, hydrogen oxide fuel cells
It's hard to teach
Ideas and methods for designing chemical power sources using the principles of the original battery
Teaching process
Teaching
Link
Teacher activities
Student activities
Design intent
Introduction of new lessons
[introduced] brief introduction to the magic portable phone charger
What happens to positive and negative poles in copper and zinc batteries? How is the current generated
[retrospect] the original battery is a chemical-to-electric device. A review of the working principles of the pool, re-evalidation of the oxidation reaction and reduction reaction are carried out in an orderly process of electronic transfer at the diodes, thus forming the current。
Inspired students to learn new knowledge
A review of the acquired original battery principles provides the basis for a deeper understanding of the chemical power source principles at the end。
Theoretical exploration: brief chart of the installation and operation of alkaline zinc dry manganese batteries and lead batteries
There is a significant gap between the original battery and the various chemical power sources in life. Question asked: what factors should scientists consider when designing chemical power sources based on the principles of the original battery? The students are invited to take stock of:
Positive thinking:
Analysis of the problems that scientists have to address when designing chemical power sources based on life experience in understanding differences between original batteries and chemical power sources
Energy, raw materials, safety, environmental protection
Students' perception of the difference between the original battery in the laboratory and the chemical power source in life has risen to rationality. Actively reflect on considerations and solutions for designing chemical power sources based on original batteries。
Encourage students to rely on two oxidizing response equations
Consider the design of chemical power sources using original battery principles。
Summary maps of two chemical power sources, alkaline zinc dry manganese batteries and lead batteries, commonly used in design life。
Most of the students designed two devices along the lines of the original battery, which may be partly considered in terms of whether metal oxides can be directly electrodes, soluble concentrations, solid surface areas and salt bridges。
Deepening the understanding of the principles of the original battery, the differences between the design of the chemical power source and the design of the original battery, and the complexity of the design of the chemical power source
Compare the actual internal construction of alkaline zinc dry manganese batteries and lead batteries. The students were guided to the electrode reaction equation。
A positive comparison of the actual structure within the two batteries with the same and different points of their own design。
The comparison improved the tectonic and theoretical understanding of the two chemical power sources, as well as the essentials of the design of the chemical power sources
Experiment
Explore: meteorograms and working principles for hydrogen fuel cells
Direct student analysis:
How can hydrogen and oxygen, the reactive feedstock of hydrogen fuel cells, be lost to electrons? How do we design the device sketches for hydrogen fuel cells
Students mimic the treatment of manganese dioxide and lead dioxide and paint it on the electrode surface of the conductor, but students are not sure if the gas can be adsorbed in solids
Students are already aware of the way in which manganese dioxide and lead dioxide are electronized on the surface of the conductor electrodes, where they can migrate analogies。
Students are encouraged to experiment on whether to electrolyse hydrogen oxygen and then experience electrical currents by making electrodes in graphite。
Student experiments:
Visual experience of real experience is the most living educational material, and the current gauge points tend to reinforce student speculation. Experimental phenomena are combined with theoretical speculation, and chemical experiments are being studied in chemistry
It's important。
Showcasing experimental teaching aids: the hydrogen fuel cell tester demonstration experiments: the hydrogen fuel cell tester turns small fans。
Watch and wait for miracles
The close range generates electricity from hydrogen fuel cells and deepens understanding of how the fuel cells convert chemical energy into electrical energy
Looking ahead to chemical power sources
It's a question for students:
Who will be the main player in the chemical power supply in the future
Difficulties in developing fuel cells
Feel it
Think
