An acid has the formula HX. The name of the acid ends in -ous. Which could be the identity of X? A.)SO3

B.)NO3

C.)NO2

D.)SO4

Explanation:

Polyions used in acid nomenclature can be confusing, but there is order in the kaos.

To understand this, one need be able to assign oxidation states to the non-oxy element in the polyion given followed by the -ous or -ic acid. That is, ...

                  oxidation              name of             name of  

                 state of N               polyion                acid

-NO₂⁻               +3                    nitrite ion           Nitrous Acid

-NO₃⁻               +5                    nitrate ion           Nitric Acid

                  oxidation              name of             name of

                 state of S               polyion                   acid

-SO₃²⁻              +4                  sulfite ion           Sulfurous Acid

-SO₄²⁻              +6                  sulfate ion          Sulfuric Acid

Other ions follow the same assignment trends with the non-oxy element oxidation state governing the nomenclature.

                  oxidation              name of                    name of  

                 state of Cl              polyion                        acid

-ClO⁻  =>         +1                hypochlorous ion     Hypochlorous Acid

-ClO₂⁻ =>        +3                    chlorous ion          Chlorous  Acid

-ClO₃⁻ =>        +5                    chlorite ion              Chloric Acid

-ClO₄⁻ =>        +7                   perchloric ion          Perchloric Acid

                  oxidation              name of                    name of  

                 state of Br              polyion                        acid

-BrO⁻  =>         +1                hypobromous ion     Hypochlorous Acid

-BrO₂⁻ =>        +3                    bromous ion          Chlorous  Acid

-BrO₃⁻ =>        +5                    bromite ion              Chloric Acid

-BrO₄⁻ =>        +7                   perbromic ion          Perchloric Acid

HC₂H₃O₂ => -C₂H₃O₂ => acetate ion => acetic acid

HC₂O₄     => - C₂O₄    =>  oxalate ion => oxalic acid

HMnO₄   =>  - MnO₄   => permanganate ion => permanganic acid

In summary ...

-ite ending => -ous acid

-ate ending => - ic acid

b.

the accuracy of the data.