DraconicAcid - 8-9-2014 at 09:23
First, you shouldn't draw the sodium-oxygen interaction as a covalent bond. It's ionic, so there is no shared pair of electrons, and no line.
Second, don't draw your product as a radical or diradical. Those aren't usually stable.
You're short a pair of electrons in the first structure. It should have a lone pair on the rightmost nitrogen, a single bond to the rightmost oxygen,
and three lone pairs on that oxygen.
I suspect you're more likely to get NaNO2 + N2O --> NaNO3 + N2
franklyn - 8-9-2014 at 09:32
Here , check my work , and correct if need be
Left exposed to air Sodium Nitrite NaNO2 oxidizes slowly back to nitrate.
It appears to me from the lewis dot diagram that in the same way Sodium Nitrite NaNO2 can possibly add Nitrous Oxide N2O.
. . . . . . . . O
.. . . . . . . . ||. . . :
Na—O—N—N = N = O
. . . . . . . . .•
. . . . . . . . O
. . . . . . . . .|. . . .:. . .
:
Na—O—N = N—N = O
. . . . . . . . .•
. . . . . . . . O
. . . . . . . . .|
Na—O—N—NΞN—O •
. . . . . . . . .:
. . . . . . . . O
.. . . . . . . . ||
Na—O—N—NΞN—O •
_________________________________________________
@ DraconicAcid
Awesome , the way you anticipated my post 
The layout in text format does not easily depict structures well
I drew these instead. Clearly there are several ways to connect the dots realizing some resonance tending to stablility.
Sodium Peroxynitrite is only stable if kept in very caustic media. Enviornmental circumstances are always determining.
[Edited on 9-9-2014 by franklyn]
Eddygp - 16-9-2014 at 12:10
How did DraconicAcid answer before the question was posted??
Is this a sort of Jeopardy?
DraconicAcid - 16-9-2014 at 17:24
I'm just that good.
Franklyn, your top two structures are acceptable resonance structures. The bottom one has too much charge separation, and will not be a significant
contributor.