中学化学考试中 ,经常出现比较电解质溶液中离子、分子物质的量浓度大小关系的试题 ,涉及到盐类水解和缓冲溶液等。本文对解答这类试题给以概括性论述。一、电中性原则在电解质溶液中 ,各种阳离子所带正电荷数的总和等于各种阴离子所带负电荷数的总和。例如在Ｎａ2 ＣＯ3的水溶 In middle school chemistry exams, questions concerning the relationship between the amount and concentration of ions and molecular substances in electrolyte solutions often appear, involving the hydrolysis of salts and buffer solutions. This article gives a general discussion of answering such questions. First, the principle of electricity neutrality in the electrolyte solution, the total number of positive charges carried by various cations is equal to the sum of the number of negative charges carried by various anions. For example, in the water solution of Na2CO3