The basic form of teaching design of chemistry inquiry experiment in middle school. Combined with teaching practice, it is emphasized to use inquiry teaching to cultivate students' ability to ask, analyze and solve problems, to cultivate students' ability to collect and process information, and to cultivate students' innovation and exploration ability. This paper probes into the basic forms of teaching design of middle school chemistry inquiry experiment from the aspects of teaching content, teaching process, teaching media resources and teaching evaluation.
Specific methods can refer to the following specific cases:
Exploration of open experiment: exploration of reaction products of metal sodium and copper sulfate dilute solution
3. 1 introductory questions
Through the study of "alkali metal elements" and the teacher's classroom demonstration experiment, students have mastered the physical and chemical properties of sodium and understood the experimental phenomena and reaction products of sodium and water. On this basis, the teacher guides students to think about what products will be obtained when sodium with very active properties reacts with copper sulfate solution. According to the knowledge that the metal activity of sodium is stronger than that of copper, some students do not hesitate to task: sodium can replace copper in copper sulfate; Some students also have questions: Does sodium react with water or replace copper first? At this time, through the guidance of teachers, a good "focus" of inquiry is formed.
3.2 conjecture and hypothesis
Teachers can organize students to discuss in groups and put forward their own ideas on the problem. The class's guesses and assumptions are mainly divided into two categories. One is that sodium replaces copper in copper sulfate first, resulting in red precipitate of copper and sodium sulfate solution; Second, sodium reacts with water to generate sodium hydroxide and hydrogen, and then sodium hydroxide reacts with copper sulfate to generate blue copper hydroxide precipitate.
3.3 put forward the experimental scheme
Because of the openness of the research topic, each group of students put forward various experimental schemes. To sum up, the main parts are basically the same: take a piece of metallic sodium the size of mung bean, wash kerosene with filter paper, put it into a large test tube, and add copper sulfate solution into the large test tube with a separatory funnel. Some experimental groups added other experimental equipment to verify the hydrogen produced in the experiment. There are two typical types: one is to introduce gas into a hot copper oxide test tube with a catheter. The other is.
3.4 experimental inquiry, experimental phenomena
Through grouping experiments, students mainly get the following realization images.
project
number of people
Conjectures and assumptions
Predicting experimental phenomena
Experimental phenomenon
9 groups (32 people)
Production of copper hydroxide
Blue flocculent precipitate is produced and hydrogen gas is released.
Blue flocculent precipitate is produced and hydrogen gas is released.
The fourth group (16 people)
Production of copper hydroxide
Blue flocculent precipitate is produced and hydrogen gas is released.
The third group (12 people)
Substitute copper
Produce red copper oxide precipitate.
Blue flocculent precipitate is produced.
3.5 Explain communication
When the students finished the experimental exploration, they cooperated with each other and finally came to a conclusion. Firstly, sodium metal reacts with water in copper sulfate solution to generate sodium hydroxide, releasing hydrogen, and then sodium hydroxide reacts with copper sulfate to generate blue copper hydroxide precipitate. In some experiments, blue copper hydroxide precipitated a black solid substance, which is copper oxide. After discussion, the students think that the reaction between metal and water is a violent exothermic reaction, and the released heat can decompose some copper hydroxide. For this problem, two students put forward in the experimental report that because the density of water molecules in copper sulfate solution is higher than that of copper ions, it is equivalent to generating hydrated copper sulfate, and copper ions are surrounded by water molecules, so sodium reacts with water first.
3.6 Teacher evaluation
Through exploratory experiments, most students have mastered the experimental process and phenomena, and can put forward reasonable and firm principles for the phenomena. By consulting students' experimental reports, it is found that most students did not fill in the column of records of members of the same group, which shows that students' awareness of cooperative discussion is still weak and they are not good at recording. In the part of self-evaluation, the students wrote: "To tell the truth, I prefer experiments, and I prefer to find special situations from experiments to study. Of course, I have to be careful when doing experiments. Many things are experimental. " "As long as the experimental operation is standardized and there is a certain knowledge base, you can cultivate your own experimental interest and find out the experimental methods"; "This experiment not only exercises our hands-on ability, but also allows us to draw conclusions through experiments, which can improve our interest. We have a strong experimental operation, a good knowledge base and are very interested in experiments. The experimental method needs to be further improved. I hope we can have more opportunities to do experiments "; "I think that in the experiment, our hands-on ability is poor. From the experimental results, my thinking ability is not comprehensive enough and my foundation is not solid enough; Through this experiment, we not only increased our extracurricular knowledge, but also made me experience that we should be strict with objective facts, and so on. The self-evaluation of students shows that all students are interested in the experiment, and it is suggested that more opportunities be provided in the future. Most students think that their knowledge base is good, and students generally have a low evaluation of their experimental operations and methods. In the evaluation part of the same group members, students' scores are mostly "very good or better", and there is no grade, so mutual evaluation is better.
4 conclusion
Looking back on the historical changes and vigorous development of inquiry experiment teaching today, we clearly realize the significance of inquiry experiment teaching in senior high school chemistry in the current chemical education and teaching reform, and deeply analyze the basic process of implementing inquiry experiment teaching in senior high school chemistry teaching. We fully realize the important value of inquiry experimental teaching in cultivating students' experimental inquiry ability and spirit, experiencing the process of scientific inquiry, mastering the basic methods of scientific inquiry, giving full play to students' cooperative learning and team spirit, and forming a rigorous and meticulous scientific attitude of seeking truth from facts. From the perspective of epistemology, this paper expounds the epistemological functions of inquiry experiment teaching in chemistry teaching, such as asking questions, understanding the process of scientific inquiry, providing students with scientific knowledge, testing chemical theories and verifying chemical hypotheses.
Looking forward to the future, with the full implementation of the new curriculum reform, the research of inquiry experimental teaching will be gradually refined, and the practice of inquiry experimental teaching will be more and more abundant. It will become one of the main means of chemistry teaching in senior high schools and a fertile ground for school-based curriculum development in senior high schools. With the development of economy, the instruments, equipment and conditions of chemical experiments are becoming more and more perfect, and I believe that the prospect of inquiry experiment teaching in senior high school will be more and more beautiful.
Blue flocculent precipitate is produced, which is mixed with black solid to release hydrogen.