How many moles of black iron oxide Fe3O4 can be produced from 9.2 moles of water and 3.4 moles of iron?Which is the limiting reactant and how many mol of the excess reactant wil be left afte the react

Answer 1

3Fe + 4H₂O ==> Fe₃O₄ + 4H₂ ... balanced equation

To find limiting reactant just divide mols of each reactant by the corresponding coefficient in the balanced equation and see which is the least value.

For Fe we have 3.4 mols / 3 = 1.13

For H₂O we have 9.2 mols / 4 = 2.3

1.13 is less than 2.3 so Fe IS LIMITING.

To find mols of product, we use MOLES OF LIMITING REACTANT as follows:

3.4 mols Fe x 1 mol Fe₃O₄ / 3 mols Fe = 1.13 mols Fe₃O₄ can be produced

To find mols of excess (H2O) reactant, find mols used up and subtract from mols originally present.

moles H2O used up = 3.4 mols Fe x 4 mols H2O / 3 mols Fe = 4.53 mols H2O used

moles H2O left over = 9.2 mols - 4.53 mols = 4.7 mols H2O left over (2 sig. figs.)