By analogy with phosphorus compounds, name the following: \(\mathrm{Na}_{3} \mathrm{AsO}_{4}, \mathrm{H}_{3} \mathrm{AsO}_{4}, \mathrm{Mg}_{3}\left(\mathrm{SbO}_{4}\right)_{2}\)

Both phosphorus (P) and arsenic (As) are in Group 15 of the periodic table, while antimony (Sb) is in the same group. This means that their chemical behavior is similar and we can use this knowledge to make analogies with phosphorus compounds.

In each of the given compounds, we have a metal (sodium, hydrogen, or magnesium) and a non-metal element that forms an anion, a negatively charged ion, in the compounds: \(\mathrm{Na}_{3} \mathrm{AsO}_{4}\): Here, AsO4 is an anion, which is analogous to the phosphate (PO4) anion in phosphorus compounds. As the compound ion is arsenate (AsO4)³⁻, we can name it as sodium arsenate. \(\mathrm{H}_{3}\mathrm{AsO}_{4}\): In this case, we have the same arsenate (AsO4)³⁻ anion, but with hydrogen as the cation. Thus, we can name this compound as arsenic acid. \(\mathrm{Mg}_{3}\left(\mathrm{SbO}_{4}\right)_{2}\): Here, the compound ion is antimonate (SbO4)³⁻, which is analogous to the phosphate anion. It forms a compound with magnesium, so we can call it magnesium antimonate.

Now that we have identified and named both the metal and the anion in each compound, we can combine them to give the full name for each compound: 1. \(\mathrm{Na}_{3} \mathrm{AsO}_{4}\): Sodium Arsenate 2. \(\mathrm{H}_{3}\mathrm{AsO}_{4}\): Arsenic Acid 3. \(\mathrm{Mg}_{3}\left(\mathrm{SbO}_{4}\right)_{2}\): Magnesium Antimonate