The compound of which P 4 O 6 is the anhydride is ________.

The anhydride has the formula P 4 O 6 which can be written as (HPO3)2. The compound that would form this anhydride would have one less oxygen atom than (HPO3)2, which is H2PO3, also known as phosphorous acid. Therefore, the only choice that fits this description is C, which is H 3 PO 3 .

The compound of which P 4 O 6 is the anhydride is ________.

The anhydride has the formula P 4 O 6 which can be written as (HPO3)2. The compound that would form this anhydride would have one less oxygen atom than (HPO3)2, which is H2PO3, also known as phosphorous acid. Therefore, the only choice that fits this description is C, which is H 3 PO 3 .