Question

When 2.0 mol h2o react with 2.0 mol fe in the reaction below, 1.5 mol of fe are used up in the reaction. how many moles of fe are left over unreacted? 3 fe + 4 h2o → fe3o4 + 4h2?

Answer 1

The answer is 0.5 mol Fe left over.
Hope this helped! (:

Answer 2

Answer: 0.5 moles

Explanation: The given balanced equation is:

$3Fe+4H_2O\rightarrow Fe_3O_4+4H_2$

From the above equation, 4 moles of water reacts with 3 moles of Fe. So, mole ratio of water to Iron is 4:3.

If we take 2.0 moles of water and 2.0 moles of Fe then water will be the limiting reactant.

The given information says, 1.5 moles of Fe are used. We can also calculate how many moles of Fe are used as:

$2.0molH_2O(\frac{3molFe}{4molH_2O})$  = 1.5 mol Fe

So, 2.0 moles of Fe were taken and 1.5 moles of it were used then left over moles of Fe = 2.0 moles - 1.5 moles = 0.5 moles

Hence, 0.5 moles of Fe will be left over underacted.