Question

question 21
what is the systematic name for p2o5?
phosphorus pentoxide
diphosphorus dioxide
phosphorus oxide
diphosphorus pentoxide
diphosphorus oxide

Explanation:

When naming binary covalent compounds, we use prefixes to indicate the number of each type of atom. The prefix for 2 is "di -" (for phosphorus atoms, so "diphosphorus") and the prefix for 5 is "penta -" (for oxygen atoms, but the ending of the prefix for the second element is changed to "-oxide", so "pentoxide").

Answer:

diphosphorus pentoxide