chemistry
posted by gwen .
The rusting of iron is represented by the equation 4Fe + 3O2 2Fe2O3. If you have a 1.75mol sample of iron, how many moles of Fe2O3 will there be after the iron has rusted completely?

The coefficients tell you.
4 mols Fe = 2 mols Fe2O3.
1.75 x (2/4) = ?