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在农村中学如何进行水的反常膨胀现象及其规律的实验是一难点。现将我的做法提供给同行。取一根大号截底玻璃试管,将插有温度计的橡皮塞于塞在原试管口,然后倒过来作试管的底。整个装置如图所示。在试管里装进冰水混合物,见到温度计的示数是0℃。用适当火焰的酒精灯缓缓地在这试管上口端A处加热,同时引导学生观察,便见管里冰水混合物里的碎冰片逐步上升到加热处。只要水里还有冰片,温度计的示数总保持0℃。然后再加热,细细的观察温度计的示数
It is difficult to conduct experiments on how to conduct abnormal expansion of water and its laws in rural middle schools. Now provide my practice to my colleagues. Take a large cut-off glass test tube, insert a rubber plug with a thermometer in the original tube, and then use it as the bottom of the tube. The entire device is shown in the picture. The test tube was filled with a mixture of ice and water and the thermometer was shown at 0°C. With an appropriate flame of alcohol lamp slowly heated at the upper end of the tube A, while guiding the students to observe, see the ice pieces in the tube of ice water mixture gradually rose to the heating. As long as there is borneol in the water, the thermometer is always kept at 0°C. Then heat and observe the thermometer