N2O5 is named as dinitrogen pentaoxide it has NO2+ and NO3-
with average mass of 108.01
Systematic name 1,3-Dioxodiazoxane 1,3-dioxide
Also know as
Nitrogen pentoxide (O2NONO2)
This can be named in two ways.
Here we have two Nitrogen and 5 oxygen.
So we can say Dinitogen Pentaoxide.
Another way is to do this is by oxidation state. In `N_2O_5` oxidation state of N is 5. So we can say the name as;
Nitrogen(V) Oxide [ Nitrogen five Oxide]