Dinitrogen trioxide, N₂O₃, has the structure shown here.

The oxide is unstable, decomposing to NO and NO₂ in the gas phase at 25°C.

(a) Draw resonance structures for N₂O₃ and explain why one N—O bond distance is 114.2 pm, whereas the other two bonds are longer (121 pm) and nearly equal to each other.
(b) For the decomposition reaction, Δ_rH° =+40.5 kJ/mol and Δ_rG° = −1.59 kJ/mol. Calculate ΔS° and K for the reaction at 298 K.
(c) Calculate Δ_fH° for N₂O₃(g).

Transcribed Image Text:

O 114.2 pm N-N 121 pm 190⁰