S.38 1-27

a)
HCl\left(aq\right){,}\ tiheys=1{,}18\frac{kg}{dm^3}{,}\ m-\%=36\%
c=\frac{n}{V}=\frac{m}{MV}=\frac{\rho}{M}
c\left(HCl\right)=\frac{0{,}36m}{MV}=\left(\rho=\frac{m}{V}\right)=\frac{0{,}36\rho}{M}=\frac{\left(1180\frac{g}{l}\cdot0{,}36\right)mol}{\left(1{,}008+35{,}45\right)\frac{g}{mol}}=11{,}6517...\approx12\frac{mol}{dm^3} 

b)
NH_3\left(aq\right){,}tiheys=0{,}91\frac{kg}{dm^3}{,}\ m-\%=25\%
c=\frac{n}{V}=\frac{m}{MV}=\frac{\rho}{M}
c\left(NH_3\right)=\frac{0{,}25m}{MV}=\left(\rho=\frac{m}{V}\right)=\frac{0{,}25\rho}{M}=\frac{\left(910\frac{g}{l}\cdot0{,}25\right)mol}{\left(14{,}01+1{,}008\cdot3\right)\frac{g}{mol}}=13{,}355...\approx13\frac{mol}{dm^3}