Q.Give the resonating structures of NO2 and N2O5.

Step 1: $NO_2$ resonance.

$NO_2$ has one unpaired electron on nitrogen (17 valence electrons total, odd number) and is bent/angular. It is represented as a resonance hybrid of two equivalent structures in which the N=O double bond and the N–O single bond (and the odd electron) are interchanged between the left and right oxygen atoms:

(the odd electron is formally shown on N, delocalised over the N–O framework in the true hybrid), giving both N–O bonds equal, intermediate bond order/length in the real molecule.

Step 2: $N_2O_5$ structure.

$N_2O_5$ (dinitrogen pentoxide) consists of two planar $NO_3$ (nitrate-like) units connected through a bridging oxygen atom (–O–), i.e. $O_2N$–O–$NO_2$, with each terminal $NO_2$ group itself carrying a positive nitrogen bonded to two terminal oxygens.

Step 3: $N_2O_5$ resonance.

Each terminal $–NO_2$ group (like the nitrate ion) is a resonance hybrid, with the N=O double bond character delocalised between its two terminal oxygen atoms:

$O=N(-O-)-O^- \;\leftrightarrow\; ^-O-N(-O-)=O$ …

Draw NO2's odd-electron structure and show the two resonance forms with the double bond/odd electron swapped between oxygens; then describe N2O5's bridged-dinitrogen struct …

• Do not forget NO₂ is an odd-electron (paramagnetic) species — students often try to pair all electrons and miss the radical resonance structure.
• N₂O�5 is not a single NO2-type unit — it is two nitrogen centres bridged by an oxygen (O₂N–O–NO₂); failing to show this bridging oxygen is a common structural mistake. …