I’m pretty sure it’s either stormy it snowy :)
Answer : The enthalpy of formation of 
is, -812.4 kJ/mole
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The formation of will be,
The intermediate balanced chemical reaction will be,
(1) 
(2) 
(3) 
(4) 
Now adding all the equations, we get the expression for enthalpy of formation of will be,
Therefore, the enthalpy of formation of is, -812.4 kJ/mole
Answer: c
that is the answer
There are 3 equations involved in manufacturing Nitric Acid from Ammonia.
First the ammonia is oxidized:
4NH3 + 5O2 = 4NO + 6H2O
Then for the absorption of the nitrogen oxides.
2NO + O2 = N2O4
Lastly, the N2O4 is further oxidized into Nitric acid.
3N2O4 + 2H2O = 4HNO3 + 2NO
Then run stoichiometry through these equations.
The first equation produces roughly 271,722,938 grams of NO
The second equation produces roughly 416,606,944 grams of N2O4
The last equation produces roughly 380,412,294 grams of HNO3 (nitric acid)
Convert the exact number back into tons, and your answer is: <span>419.332775 tons.
</span>
Rounded, I'm going to say that's 419.33 tons.
Hope this helps! :)
Also, it seems that commercially, Nitric Acid is commonly made by bubbling NO2 into water, rather than using ammonia.
