posted by jason .
Use the reaction shown to calculate the mass of iron that must be used to obtain 0.500 L of hydrogen at STP: 3Fe(s) + 4H2O(l) pr029-1.jpg Fe3O4(s) + 4H2(g
mols H2 needed = 0.500L/22.4L = ? at STP.
mols Fe needed = 3/4 that (see the coefficients in the balanced equation.)
g Fe = mols x atomic mass.