What is the approximate ΔH in kJ for the following reaction as written:

Question

2NH3(g) --> 3H2(g) + N2(g)

Careful, what kind of bond does the nitrogen molecule make?

Answer 1

Frankly I don't see that the kind of bond N2 makes is relevant.
dHrxn = (n*dHformation products) - (n*dHf reactants)
Look up the dH formation for products and reactants and solve for dHrxn.
Hint in solving: dHformation H2 and dH formation N2 are zero by definition.