name the acid: h₃po₃\nhydrophosphoric acid\nphosphorous acid\nphosphoric hydroxide\nphosphoric acid

Answer:

B. phosphorous acid

Explanation:

Step1: Recall acid - naming rules

For oxy - acids with the general formula (H_aX_bO_c), if the central atom (X) has a lower oxidation state, the acid name has the suffix “-ous”. In (H_3PO_3), the oxidation state of phosphorus ((P)) is + 3. Phosphoric acid ((H_3PO_4)) has (P) in a + 5 oxidation state. Hydrophosphoric acid is (PH_3) which is not an oxy - acid. Phosphoric hydroxide is not a correct name for (H_3PO_3). So (H_3PO_3) is named phosphorous acid.