Answer : The heat of the reaction is, 399.784 kJ
Explanation :
The given balanced chemical reaction is,

First we have to calculate the moles of iron.

Now we have to calculate the moles of 
From the reaction we conclude that,
As, 4 moles of Fe react to give 2 moles of 
So, 0.968 moles of Fe react to give
moles of 
Now we have to calculate the heat of the reaction.
As, 1 mole of
produce heat = 826.0 kJ
So, 0.484 mole of
produce heat = 
Therefore, the heat of the reaction is, 399.784 kJ