Answer : The amount of heat released by the reaction is, 20.2 kJ
Explanation :
First we have to calculate the number of moles of  .
.

Molar mass of  = 77.98 g/mole
 = 77.98 g/mole

Now we have to calculate the heat released during the reaction.
The balanced chemical reaction is:

From the reaction we conclude that,
As, 2 moles of  releases heat = 126 kJ
 releases heat = 126 kJ
So, 0.320 moles of  releases heat =
 releases heat = 
Therefore, the amount of heat released by the reaction is, 20.2 kJ