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有关含有离子内容的化学计算题,是近年来在各类考试中出现的一种新题型,是考查学生分析和解决问题能力的好题。为了便于学生掌握这类题的解法,现选三例解析如下: 例1 在化合物M(OH)_x中,元素M与OH~-的质量比为9:17,已知该化合物的式量是78。则该分子中OH~-的个数是__。 解析:在化合物M(OH)_x中,设元素M的原子量为m,由题意可得 m:17x=9:17,
The question of chemical calculations involving the content of ions is a new type of question that has emerged in various examinations in recent years. It is a good question for students’ ability to analyze and solve problems. In order to facilitate the students to grasp the solution of this type of problem, the following three cases are analyzed as follows: Example 1 In the compound M(OH)_x, the mass ratio of the element M to OH~- is 9:17, and the formula of the compound is known to be 78. The number of OH~- in the molecule is __. Analysis: In the compound M(OH)_x, let the atomic weight of the element M be m, which can be obtained from the question m:17x=9:17,