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在课堂演示实验教学中,如何培养学生的能力,发展学生的智力,我结合初中化学《混和物的分离》中[实验4-10]的教学探索,谈点体会。[实验4-10] 在烧杯里加入10克硝酸钾和食盐的混和物(食盐的量较少)。注入15毫升水,加热,使混和物完全溶解,然后冷却,观察硝酸钾晶体的析出。再进行过滤(图4-9),硝酸钾晶体留在滤纸上,食盐仍然溶解在滤液里。为什么? 做完以上实验后,我指导学生阅读了课本中与实验提出的问题有关的一些内容。之后,有学生问:为什么这个实验叙述中说“食盐仍
In the demonstration of experimental teaching in class, how to cultivate the students 'abilities and develop the students' intelligence, I talked about the teaching and exploration of [Experiment 4-10] in junior high school chemistry. [Experiment 4-10] A mixture of 10 g of potassium nitrate and salt (less amount of salt) was added to a beaker. Inject 15 ml of water, heat to completely dissolve the mixture and then cool down to observe the precipitation of potassium nitrate crystals. Then filter (Figure 4-9), potassium nitrate crystals remain in the filter paper, salt is still dissolved in the filtrate. Why? After completing the above experiment, I instruct the students to read some of the textbooks related to the questions posed by the experiment. After that, a student asked: Why did this experiment say "salt is still