在讨论酸碱平衡中氢离子浓度的近似计算时,大多用“大于”或“小于”作为忽略项的条件,其中有的选定倍数或特定数值,有的不注明数值;也有用浓度对数图来判别次要组分忽略与否。虽然这些方法都是根据允许计算相对误差(E)来确定的,但是没有一个直接与允许计算误差相关的表达式。曾提出用“比较数 When discussing the approximate calculation of the hydrogen ion concentration in the acid-base balance, most of them are the conditions of ignoring the terms “greater than” or “less than”, some selected multiples or specific values, and some do not indicate the values; Number of figures to determine whether the secondary components ignored or not. Although these methods are all based on allowing the relative error (E) to be calculated, none of the expressions are directly related to the allowable calculation error. Have proposed to use "comparison number