HCl is composed of hydrogen and chlorine. In binary acid nomenclature, the name is formed by adding the prefix 'hydro-' to the root of the nonmetal, followed by 'ic acid', which results in hydrochloric acid.

Nitric acid is derived from the nitrate ion (NO3 - ) so its correct formula is HNO3. The other formulas either correspond to different acids or are non-existent.

Binary acids consist of hydrogen and one nonmetal. They are named by adding the prefix 'hydro-' to the root of the nonmetal, followed by 'ic acid'.

HBr is composed solely of hydrogen and bromine, making it a binary acid. The other acids contain oxygen and are classified as oxoacids.

Oxoacids derived from anions ending in '-ate' change the suffix to 'ic acid' when named. This rule helps to differentiate them from acids derived from '-ite' anions, which use 'ous acid'.

HNO2 is formed from the nitrite ion (NO2 - ) and is named nitrous acid according to the nomenclature rules for oxoacids. This distinguishes it clearly from HNO3, which is nitric acid.

Sulfurous acid is associated with the sulfite ion (SO3^2 - ) and its correct formula is H2SO3. H2SO4, in contrast, is sulfuric acid which is derived from the sulfate ion.

When an oxoacid is derived from an anion ending in '-ite', the acid is named with the suffix 'ous acid'. This contrasts with anions ending in '-ate', which convert to 'ic acid'.

Phosphoric acid (H3PO4) contains oxygen along with hydrogen and phosphorus, making it an oxoacid. The other acids listed are binary acids and do not contain oxygen in their composition.

Carbonic acid forms when carbon dioxide dissolves in water, resulting in the formula H2CO3. The other options do not correctly represent carbonic acid.

The perchlorate ion (ClO4 - ) gives rise to perchloric acid when protonated. This follows the rule for oxoacids derived from anions ending in '-ate' to be named with 'ic acid'.

Although H3PO3 contains three hydrogen atoms, only two of them are ionizable. This leads to its correct name, phosphorous acid, distinguishing it from phosphoric acid (H3PO4) where all three hydrogens are replaceable.

Hypochlorous acid contains one oxygen atom and is represented by the formula HClO. The other formulas correspond to acids with a greater number of oxygen atoms attached to chlorine.

In the naming of binary acids, only the halogen's name is modified by adding a 'hydro-' prefix and replacing the ending with 'ic acid'. Hydrogen remains unchanged, which is key to correctly naming these acids.

HBrO3 contains the bromate ion (BrO3 - ) and, following the rules for oxoacid nomenclature, its name is derived by replacing the '-ate' suffix with 'ic acid', resulting in bromic acid. This method clearly distinguishes it from other similar acids.

Hyponitrous acid is formed from the hyponitrite ion and its correct formula is H2N2O2. This distinguishes it from nitrous acid (HNO2), which is a different compound entirely.

HClO4 contains the perchlorate ion (ClO4 - ) and is named perchloric acid by replacing the '-ate' ending with 'ic acid' and using the 'per-' prefix to denote the highest oxygen content. This clear nomenclature helps differentiate it from other chlorine oxoacids.

HNO2 produces the nitrite ion (NO2 - ), making the pairing correct. The other pairings incorrectly match the acids with their corresponding anions, which is a common error in acid nomenclature.

Phosphorous acid (H3PO3) is diprotic because only two of its three hydrogen atoms are ionizable. This characteristic is important to note as it distinguishes phosphorous acid from phosphoric acid, which is triprotic.

In acid nomenclature, the prefix 'hydro-' is reserved exclusively for binary acids. Oxoacids utilize changes to the suffix based on the oxygen content and oxidation state of the central atom, making this the correct statement.