Multiple choice Which of the following oxoacids of phosphorus are diprotic acids? Hypophosphorus acid and Phosphorous acid Phosphorous acid and Phosphoric acid Phosphoric acid and metaphosphoric acid Hypophosphorus acid and Pyrophosphoric acid Phosphorous acid and Pyrophosphorus acid Reveal answer Fill a bubble to check yourself E Correct answer Explanation Phosphorous acid (H3PO3): Diprotic acid Pyrophosphorus acid (H4P2O5): Diprotic acid