Question

把50mL含溶质1.42G的硫酸钠溶液稀成100mL,Na离子的物质的量的浓度是多少mol/L?

Answer 1

n(Na2SO4)=1.42g/142g/mol=0.01mol,n(Na+)=2n(Na2SO4)=0.02mol,

c(Na+)=n(Na+)/V=0.02mol/0.1L=0.2mol/L.