NH3 + H2O<==>NH4+ + OH-Kb(NH3)=[OH-]*[NH4+]/[NH3]=约=[OH-]*n(NH4+)/n(NH3)n(NH4+)/n(NH3)=Kb/[OH-]=1.8*10^-5 /10^-4=0.18没有氨水浓度无法计算反推: 41.8克NH4Cl的物质的量=0.781moln(NH3)=0.781mol /0.18=4.34molc(NH3)=4.34mol/ 0.350L=12.4mol/L