与水的电离和溶液酸碱性有关的试题是近年各省(区)、市高考考查的热点,也是一个难点.笔者认为,只要从以下方面入手,就能抓住核心、形成方法、快速解答.一、抓住一个思想外加物质对水的电离平衡的影响.二、围绕两个核心(1)任何温度、任何水溶液中都存在c(H~+)_(H_2O)=c(OH~-)_(H_2O).(2)K_w=c(H~+)·c(OH~-);K_w只与温度有关. Problems related to the ionization of water and the acidity and alkalinity of solution are also the hot spots in the examination of college entrance examination in various provinces (districts) and municipalities in recent years, which is also a difficult point.I think that as long as we start with the following aspects, we can grasp the core, form a method and answer quickly. First, to seize the influence of an extraneous material on the ionization balance of water.Second, around the two cores (1) at any temperature, there exists c (H ~ +) _ (H_2O) = c (OH ~ -) in any aqueous solution, _ (H_2O). (2) K_w = c (H ~ +) · c (OH ~ -); K_w is only related to temperature.