Odpowiedź :
V = 130cm³ = 0,13dm³
mNaCl = 23g
M(NaCl) = 23g/mol + 35,5g/mol = 58,5g/mol
[tex]n=\frac{ms}{M}[/tex]
[tex]n=\frac{23g}{58,5\frac{g}{mol} }=0,393mol[/tex]
[tex]Cm=\frac{n}{V}[/tex]
[tex]Cm=\frac{0,393mol}{0,13dm3} =3,02 \frac{mol}{dm3}[/tex]