学过物理后,我们知道热胀冷缩可以导致密闭容器内气体压强的变化;通过学习化学,我们又知道了气体溶解或化学反应消耗气体也会导致密闭容器内气体压强的变化;反之,通过气体压强的变化也可以反映出气体溶解、化学反应或吸热放热而产生的热胀冷缩的变化。我们举例来说明。一、测空气中氧气的含量图1测定空气中氧气含量的实验,是各省市中考 After physics, we know that thermal expansion and contraction can lead to the change of gas pressure in the airtight container. By learning chemistry, we also know that the gas dissolved or the chemical reaction consumes gas, which also leads to the change of the gas pressure in the airtight container. On the contrary, Changes in gas pressure can also reflect changes in thermal expansion and contraction caused by gas dissolution, chemical reaction or endothermic heat release. We give an example to illustrate. First, the test of oxygen in the air Figure 1 Determination of oxygen in the air experiments, provinces and cities in the test