Which is an incorrect formula for a compound containing phosphorus.

1- P4O10 2- H2PO4 3- KPF6 4- Na2HPO3 5- Ca2P

A) 3 B) 3 & 4 C) 1 & 5 D) 2 & 5 E) 1 F) 4 G) 3 & 5

I think #5 is incorrect but not sure what else.

I almost didn't figure out how you numbered/lettered. You mixed them up from question to answer and the 1- and 2- and 3- I thought were subscripts.

Ca2P should be Ca3P
H2PO3 should be (H2PO3)^-

To determine the correct answer, we need to identify the incorrect formula for a compound containing phosphorus in the provided options. Let's analyze each option:

1) P4O10: This is the formula for tetraphosphorus decoxide, which is a correct formula for a compound containing phosphorus.

2) H2PO4: This is the formula for dihydrogen phosphate, which is another correct formula for a compound containing phosphorus.

3) KPF6: This is the formula for potassium hexafluorophosphate, which is a correct formula for a compound containing phosphorus.

4) Na2HPO3: This is the formula for disodium hydrogen phosphite, which is a correct formula for a compound containing phosphorus.

5) Ca2P: This is the incorrect formula for a compound containing phosphorus. Calcium phosphide is typically represented as Ca3P2.

Therefore, the incorrect formula for a compound containing phosphorus is option G) 3 & 5.