Na reactioneaza cu apa si formeaza hidroxidul de sodiu; acesta se dizolva in restul de apa care ramane dupa consumarea sodiului in reactie
calculez masa de NaOH si de H2O care participa la reactie
2mol........2mol................2mol
2Na + 2H2O----------> 2NaOH + H2
2x23g.......2x18g..............2x40g
2,3g...........x= 1,8g.............y=4g
se formeaza 4g NaOH ,care se dizolva in m,apa=37,8-1,8=36g
c=mdx100/ms. unde ms= md+m,apa= 4g+36g=40g
c= 4x100/40=..........................calculeaza !!!!
