a,
$n_{NaCl}=0,5 mol$
$\Rightarrow m_{NaCl}=0,5.58,5=29,25g$
b,
$n_{KNO_3}=0,5.2=1 mol$
$\Rightarrow m_{KNO_3}=1.101=101g$
c,
$n_{CaCl_2}=0,25.0,1=0,025 mol$
$\Rightarrow m_{CaCl_2}=0,025.111=2,775g$
d,
$n_{Na_2SO_4}=0,3.2=0,6 mol$
$\Rightarrow m_{Na_2SO_4}=0,6.142=85,2g$
e,
$n_{NaCl}=2,5.0,9=2,25mol$
$\Rightarrow m_{NaCl}=2,25.58,5=131,625g$
f,
$n_{MgSO_4}=0,25.0,1=0,025 mol$
$\Rightarrow m_{MgSO_4}=0,025.120=3g$
