某溶液由NaCl、MgCl2、Al2(SO4)3、Na2SO4组成,已知c(Na+)=0.4mol/L,c(Al3+)="0.2" mol/L,c(Mg2+)=0.1mol/L,c(Cl-)=0.3mol/L则SO42-的物质的量浓度为
A.0.3 mol/L | B.0.4mol/L | C.0.45mol/L | D.0.55mol/L |
某溶液由NaCl、MgCl2、Al2(SO4)3、Na2SO4组成,已知c(Na+)=0.4mol/L,c(Al3+)="0.2" mol/L,c(Mg2+)=0.1mol/L,c(Cl-)=0.3mol/L则SO42-的物质的量浓度为
A.0.3 mol/L | B.0.4mol/L | C.0.45mol/L | D.0.55mol/L |