1L多大浓度的NH4CL溶液可使1g Mg(OH)2沉淀溶解?

问题描述:

1L多大浓度的NH4CL溶液可使1g Mg(OH)2沉淀溶解?
求救啊 老师

Ksp[Mg(OH)2]=5.6*10^-12;Kb(NH3.H2O)=1.8*10^-5;
2NH4+ + Mg(OH)2 = Mg2+ + 2NH3.H2O,K=Ksp/Kb.Kb=0.017
c(Mg2+)=1/58=0.017mol/L;
K=0.017*0.034*0.034/xx=0.017;x=0.034mol/L(平衡NH4+浓度)
c(NH4Cl)=0.034+0.034=0.068mol/L