P2O5 is a covalent compound used to purify sugar. What is the correct name of this compound?

• A. Diphosphorus pentoxide
• B. Diphosphorus oxide
• C. Phosphorus dioxide
• D. Phosphorus pentoxide

Answer: (A)

Verified step by step guidance

1. Identify the elements present in the compound P2O5: phosphorus (P) and oxygen (O).
2. Determine the number of atoms of each element in the formula: 2 phosphorus atoms and 5 oxygen atoms.
3. Recall the naming rules for covalent (molecular) compounds: use prefixes to indicate the number of atoms of each element (mono-, di-, tri-, tetra-, penta-, etc.).
4. Apply the prefixes to the elements: 'di-' for 2 phosphorus atoms and 'penta-' for 5 oxygen atoms, resulting in 'diphosphorus pentoxide'.
5. Note that the prefix 'mono-' is usually omitted for the first element, so 'phosphorus pentoxide' would be incomplete; the correct full name is 'diphosphorus pentoxide'.