There is a question in one of my Chemistry text books to do with bond enthalpy and I'm having trouble making sense of how to do one of the questions:
Calculate the bond enthalpy for the N≡N bond using the bond enthalpy information and the following equation:
½ N2 (g) + 1 ½ H2 (g) → NH3 (g) ΔfH = -46.5 kJ mol-1
H-H bond enthalpy = 436 kJ mol-1
N-H bond enthalpy = 391 kJ mol-1
How would I find the bond enthalpy for N≡N?
I understand how to do ∑(bonds broken) - ∑(bonds formed) but can't solve this one.
Please help.