论文部分内容阅读
福建厦门二中于少华湖北洪泽二中秦德群来信说《化学教学》82年第一期中发表的《“影响化学平衡的条件”的教学》一文,在课时安排,教学组织上是有不少可取之处的。但在演示实验中增加了在平衡体系中加入少量氯化钾晶体,以此说明增加生成物的浓度,可使化学平衡向着逆反应的方向移动,这一点是不妥当的。“我们知道,在弱电解质溶液里,加入跟它含有不相同离子的强电解质之后,使弱电解质的电离度增大,这种现象属于盐效应。在氯化铁和硫氰化钾反应的平衡体系中,加入氯化钾晶体后,溶液的血红色变浅,实际上是发生盐效应的结果。”
In the article “The Teaching of the Conditions Affecting the Chemical Balance” published in the first issue of “Chemistry Teaching” in the 82nd issue of the “Xue Shaoqun Hubei Hubei Hongze Erzhong Middle School Qinde Group”, Xiamen University, Xiamen, China, there are many teaching organizations. Advisable. However, adding a small amount of potassium chloride crystals to the equilibrium system in the demonstration experiment shows that increasing the concentration of the product can make the chemical equilibrium shift towards the reverse reaction, which is not appropriate. “We know that in a weak electrolyte solution, after adding a strong electrolyte with different ions, it will increase the ionization degree of the weak electrolyte. This phenomenon belongs to the salt effect. The balance between the reaction of ferric chloride and potassium thiocyanide In the system, the addition of potassium chloride crystals resulted in a shallow red blood solution, which was actually the result of the salt effect.”