Final answer:
The systematic names for FeCl2 and FeCl3 are iron(II) chloride and iron(III) chloride respectively in the Stock system, or ferrous chloride and ferric chloride in the common system. The Roman numeral indicates the charge on the iron ion.
Step-by-step explanation:
To provide the systematic name of a compound like FeCl (which should be FeCl2 or FeCl3), the Stock system of nomenclature is used for metals that have more than one possible ionic charge. Type II ionic compounds, such as iron chlorides, change their name depending on the iron ion's charge. When iron has a charge of 2+, the compound is named iron(II) chloride. Conversely, when iron has a 3+ charge, as evidenced by the presence of three chloride ions (Cl−) in the compound, it is named iron(III) chloride.
In the common system of nomenclature, these compounds would be called ferrous chloride for FeCl2 and ferric chloride for FeCl3. This is an older nomenclature style that uses different suffixes (-ous and -ic) to reflect the iron’s lower and higher oxidation states respectively.