What is the systematic name for aqueous H₃PO₃?

Question

Quizplus · Accepted Answer

The systematic name for aqueous H₃PO₃ is phosphorous acid. This is because it has the formula H₃PO₃, which indicates the presence of the ion H₂PO₃⁻. In this ion, there is one P atom and two O atoms, which means that the P atom has a +3 oxidation state. According to IUPAC rules, the name for an acid containing this ion is "hydrogen [stem]ate", where [stem] represents the name of the anion with the "-ate" ending replaced by "-ous". In this case, the correct stem is "phosphor", which makes the name "hydrogen phosphorousate" (not an option) without the "-ate" ending. Finally, the word "hydrogen" is replaced by "phosphorous", giving the name "phosphorous acid".

What Is the Systematic Name for Aqueous H₃PO₃