Which ion corresponds to the formula AsO4(3-)?

The ion corresponding to the formula AsO4(3-) is known as arsenate. This is a polyatomic ion that contains arsenic in its +5 oxidation state, along with four oxygen atoms. The overall charge of the ion is -3, which signifies that it has three more electrons than protons.

Understanding the architecture of the ion is key; the presence of arsenic indicates it is a variant of phosphate, but since the central atom is arsenic rather than phosphorus, the correct nomenclature identifies it as arsenate. This systematic naming means that while it shares structural similarities with phosphate (PO4(3-)), it is distinct due to its arsenic content.

In contrast, the other choices refer to different entities. Arsenite, for example, represents AsO3(3-), which contains arsenic in a lower oxidation state. Phosphate is specifically the ion PO4(3-) and phosphite refers to PO3(3-). Each of these ions has a different structure and chemical behavior, which highlights the uniqueness of arsenate. Therefore, the correct identification of this particular ion as arsenate reflects its composition and properties accurately.