Răspuns:
Explicație:
M,Na= 23g/mol
M,NaOH=40g/mol
2x23g.......2x18g.......2x40g
2Na + 2H2O------> 2NaOH +H2
9,2g...........x..................y
x= 7,2g apa necesara reactiei
y= 16g NaOH este masa dizolvata in solutie, md
c=mdx100/ms---> ms= 16x100/25g=64g
dar ms=md+m,apa----> m,apa= 64g-16g=48g apa
m,apa total= 48g in solutie+7,2g in reactie