# How many covalent bonds occur in the N_2O_5 molecule?

Aug 19, 2017

Well, I count 8 bonds all together.......

#### Explanation:

A simple vesper treatment of ${N}_{2} {O}_{5}$ must distribute $5 \times 6 + 2 \times 5$ $= 20 \cdot \text{electron pairs}$ across 7 centres......

""^(-)O(O=)stackrel(+)N-O-stackrel(+)N(=O)O^-

And the given Lewis structure does distribute these electron pairs....does it not? The nitrogen centres are formally quaternized with only 4 electrons associated with the nitrogen centres, i.e. entailing a formal positive charge on each nitrogen atom, and the formally singly bound, terminal oxygen have a corresponding formal negative charge. Of course, these formal charges are delocalized by resonance.

For another example of this consider $\text{nitrate ion...}$, $O = \stackrel{+}{N} {\left(- {O}^{-}\right)}_{2}$. What is the formal charge on this ion?