--calculez masa si moli acid din solutia data
c= mdx100/ms
md= cxms/100= 0,80x400g= 320g
M,H2SO4= 98g/mol
n=m/M= 320g/98g/mol= 3,265mol H2SO4
-din ecuatie, deduc mol si masa de fier consumat
1mol......1mol
Fe + H2SO4---> FeSO4 + H2
x..........3,265mol
x= 3,265molFe
m=nxM,Fe= 3,265molx 56g/mol=.........................calculeaza !!!!