S.37 1-21


c=\frac{n}{V}

c= Konsentraatio (mol/l tai mol/dm3)
n= Aineemäärä (mol)
V= Tilavuus (l tai dm3)  
 
n\left(\left(NH_4\right)_2SO_4\right)=\frac{m}{M}=\frac{3{,}0g}{\left(14{,}01\cdot2+1{,}008\cdot8+32{,}07+16\cdot4\right)\frac{mol}{g}}=0{,}027007...mol
V\left(Liuos\right)=100ml=0{,}100l
c\left(\left(NH_4\right)_2SO_4\right)=\frac{n}{V}=\frac{0{,}023mol}{0{,}100l}=0{,}22700...\approx0{,}23\frac{mol}{l}
c\left(NH_4^{^+}\right)=0{,}227mol\cdot2=0{,}454\approx0{,}45\frac{mol}{l}

c\left(SO_4^{2-}\right)=0{,}23\frac{mol}{l}