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巧思妙解选择题是培养学生创造性思维的手段之一,也是在各种考试中取胜的关键之一。获得巧解的关键在于抓住题目中的特有条件,因题制宜地分析、推测、估算,从而寻出最简解题思路,快速准确地得到答案。一、找特殊途径例1.有5.1g镁铝合金,投入500 mL2mol·L-1的稀盐酸溶液中,金属全部溶解后,再加入4mol·L-1的NaOH溶液。若要求达到沉淀最大值,则加入NaOH溶液的体积为
Trickery Miaoyu multiple-choice questions is one of the means to cultivate students’ creative thinking, but also one of the keys to winning in various exams. The key to gain clever solution lies in grasping the unique conditions in the subject, analyzing, speculating and estimating based on the system, so as to find out the simplest solution to the problem and get the answer promptly and accurately. First, find a special way Example 1. There are 5.1g magnesium alloy, put 500mL2mol·L-1 dilute hydrochloric acid solution, the metal is completely dissolved, then add 4mol·L-1 NaOH solution. If required to reach the maximum precipitation, the volume of NaOH solution was added