Răspuns:
Avem nevoie de masele molare ale substantelor implicate in cerinta problemei M,NaOH=40g/mol M,H2O=18g/mol
se da 180g apa rezultata si se cere masa NaOH care intra in reactie
2mol......................................................2mol transform moli in grame
2NaOH + H2SO4----> Na2SO4 + 2H2O
2x40g...................................................2x18g
x....................................................................180g
x= 180x40/18 g= 400g NaOH
Explicație: