Question

name the compound N2O5?

Answer 1

Let N have an oxidation number of x, so 2x+5(-2) = 0. x = 5.
The Ox number of N here is 5.

Answer 2

....o.o
My naming knowledge says dinitrogen pentoxide.
2 Nitrogen atoms, 5 Oxygen atoms in a molecule.

Answer 3

That's right, but it's a non-IUPAC name. Google it; same thing.

Answer 4

Oh, we're doing non-IUPAC? I hate that crap.

Answer 5

I'm saying your answer is non-IUPAC. Mine is.
The point is to give a name that can be produced logically (as a result of oxidation number), not just based on grammar.

Answer 6

Oh, I gotcha.

Answer 7

Don't know that method of naming. Sorry.

Answer 8

Actually, the name you gave is also IUPAC accepted. Seems like you're right too.
Just Googled it.