Emperical and Molecular Formula: Really Simple 10 Points. It will only take you 1 minute to respond. Help?

Question

My book said the molecular formula is (P2O5)2 or P4O10

i thought that the emperical formula was (P2O5)2 or is the emperical formula simply P2O5?

Answer 1

The empirical formula is P2O5. The actual molecular formula will be the same as the empirical formula or a simple multiple of it. P4O10 is the molecular formula (actual) and P2O5 is the empirical formula (the simplest possible ratio of the atoms).

Answer 2

Phosphorus is an exception to the "rule of 8" when it comes to electrons involved in compounds.  With oxygen, it can form a series of compounds due to P-O-P bonds.    Each P can covalently bond with 5 oyxgen atoms, as P has 5 electrons in its outer shell.   So P2O5 can be formed from 2 P atoms, each attached to the same 5 oxygens.   P4O10 can also be formed, but I think the phosphorous atoms align themselves at the points of a tetrahedral pyramid.