delta_f H° for NF3(g) is -113 kJ/mol. Bond energy for the N-F bond is 273.5 kJ/mol. The bond energie — Thermodynamics and Thermochemistry Chemistry Question

💡 Solution & Explanation

1/2 $N_2$(g) + 3/2 $F_2$(g) -> NF3(g); dH = -113. Let BE($F_2$) = x, BE($N_2$) = 6x. -113 = 0.5*(6x) + 1.5*x - 3*273.5 => -113 = 4.5x - 820.5 => 4.5x = 707.5 => x = 157.22. BE($F_2$) = 157.22 kJ/mol, BE($N_2$) = 943.32 kJ/mol.