Answer: -
2 : 1
Explanation: -
To calculate the required mole ratio, the first step is writing the balanced chemical equation for the formation of Fe2O3 from Fe.
The other element present with Fe in Fe2O3 is O oxygen.
Fe reacts with oxygen to give Fe2O3.
The balanced chemical equation for this reaction is
4 Fe + 3 O 2 --> 2 Fe2O3
Now from the balanced chemical equation we see
There are 4 moles of Fe.
We also see there are 2 moles of Fe2O3.
So their ratio is Fe : Fe2O3 = 4 : 2.
For ratio, we need the simplest.
Simplifying by diving by 2, we get Fe : Fe2O3 = 2 : 1
The mole ratio between Fe and Fe2O3 is 2 : 1.