It would have helped if you had given the information "as noted below."
Look up the bond energy for N-H bond and times 3 will give you 1 mol NH3. Multiply that by 4.24.
What energy in kJ is required to break 4.24 mol of NH3 into atoms? As noted below, this information can be used to calculate ΔH for gas-phase reactions.
I got 1376.18, which is wrong.
All help is appreciated!
2 answers
True, sorry I forgot about that. I did what you said though and got it right, so thanks!