Question

In a stock system name such as iron(iii) sulfate, the Roman numeral tells us:

a) how many atoms of FE are in the formula.
b) how many sulfate ions can be attached to the iron atom.
c) the charge on each FE ion.
d) the total positive charge of the formula unit.

Answer 1

In the Stock system, the Roman numeral in a compound name like iron(III) sulfate represents the charge on each iron ion, which is 3+ in this case.

Step-by-step explanation:

In the Stock system of chemical nomenclature, the Roman numeral in a compound's name, such as iron(III) sulfate, indicates the charge on the metal ion. In this case, the Roman numeral III tells us that each iron ion (Fe) has a 3+ charge. Therefore, the correct answer to the question is (c) the charge on each Fe ion. It is also necessary to understand that the total charge of the formula unit is balanced by the negatively charged ions present in the compound. For example, in iron(III) sulfate, the sulfate ion (SO₄) has a 2- charge and to balance the charges, two sulfate ions are needed for every three iron ions.