Răspuns:
miu NaOH= 40g/mol
m=niuxmiu=0,5molx40g/mol=20g
c=mdx100/ms, unde ms=md+m,apa
md=20gNaOH
ms= 20gNaOH + 300g,apa=320g
c=20x100/320%=6,25%
Explicație:
