人教版高中化学(必修2)实验2-2吸热反应是化学教学中的重要演示实验之一。该实验是将大约20 g Ba(OH)2·8H2O晶体研细后与约10 g NH4Cl晶体一起放入烧杯中,并将烧杯放在滴有几滴水的玻璃片上,用玻璃棒快速搅拌,闻气味,用手触摸烧杯下部,并观察温度计上的读数,然后试着用手拿起烧杯,观察实验现象。教材实验装置如图1所示。 PEP High School Chemistry (compulsory 2) Experiment 2-2 The endothermic reaction is one of the important demonstration experiments in chemistry teaching. In this experiment, about 20 g of Ba (OH) 2 · 8H2O crystals were finely ground and put into a beaker together with about 10 g of NH4Cl crystals. The beaker was placed on a glass plate with a few drops of water and quickly stirred with a glass rod. Smell, touch the lower part of the beaker, and observe the readings on the thermometer, and then try to pick up the beaker by hand to observe the experimental phenomenon. Experimental teaching device shown in Figure 1.