Question

If you start with 4 moles of iron and 3 moles of oxygen to produce iron oxide, what is the limiting reagent? (You will need to balance the equation first.) Fe + O2 -> Fe2O3

Answer 1

No limiting reagent. There is an exact amount of each.

Step-by-step explanation:

Start by getting the equation

Fe + O2 -> Fe2O3

If you balance the oxygens the Fe will easily follow.

Fe + 3O2 => 2Fe2O3

So far what you have is 6 oxygens on the right and 6 on the left. Now all you need do is balance the irons. The are 4 on the right (2Fe2). So you must have 4 on the left.

4Fe + 3O2 -> 2Fe2O3

Now to your question if you have 4 mols of iron, you need 3 mols of O2. Those are the balance numbers of the equation. They also represent mols.

There is no limiting reagent in the theoretical world of chemistry. All the iron will be used up and so will the given amount of oxygen.