posted by Christian .
How many grams of water and iron must react to produce 543 g of iron oxide, Fe3O4?
3Fe + 4H2O---> Fe3O4 + 4H2
You have the balanced equation.
1. Convert 543 g Fe3O4 to moles. Moles = grams/molar mass.
2. Using the coefficients in the balanced equation, convert moles Fe3O4 to moles of what you want (moles Fe).
3. Now convert moles Fe to grams.
grams = moles x molar mass.