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1问题的提出:在中学化学教学中,对反应MgC l2+2NH3·H2O=Mg(OH)2↓+NH4C l进行方向常有争论。有人认为反应应正向进行,理由是有难溶于水的物质Mg(OH)2生成,使溶夜中离子浓度减少,符合复分解反应的条件;有人认为反应应逆向进行,理由是NH4C l水解显酸性,可与碱Mg(OH)2反应,且生成
1 The question is raised: In the middle school chemistry teaching, there is often debate over the direction of the reaction MgC l2+2NH3·H2O=Mg(OH)2↓+NH4C1. Some people think that the reaction should be carried out in a positive direction because of the formation of Mg(OH)2, a substance that is difficult to dissolve in water, so that the concentration of ions in the solution decreases, which is consistent with the conditions of the metathesis reaction. Some people think that the reaction should be carried out in reverse. The reason is that the hydrolysis of NH4Cl is obvious. Acidity, can react with alkali Mg(OH)2, and generate