What are the names of the following ionic compounds?

#"FeO"#
#"Fe"_2"O"_3#
#"CaS"#
#"NaCl"#

1 Answer
Mar 27, 2017

Answer:

Here;s what I got.

Explanation:

The thing to remember about ionic compounds that have Roman numerals in their name is that these numerals represent the oxidation state of the metal cation.

For iron(II) oxide, the #("II")# Roman numeral tells you that you're dealing with an iron cation that carries a #2+# charge.

#"Fe"^(2+) -># the iron(II) cation

The oxide anion is formed when an oxygen atom gains two electrons, which implies that it carries a #2-# charge.

#"O"^(2-) -># the oxide anion

Keep in mind that ionic compounds are neutral, so always look to have a perfect balance between the overall positive charge on the cation and the overall negative charge on the anion.

In this case, you will have

#["Fe"]^(2+) + ["O"]^(2-) -> "Fe"_ 2"O"_ 2#

Therefore, you have

#"FeO " -># iron(II) oxide

For iron(II) oxide, the #("III")# Roman numeral tells you that the iron cation carries a #3+# charge. This time, you will have

#["Fe"]^color(red)(3+) + ["O"]^color(blue)(2-) -> "Fe"_ color(blue)(2) "O"_ color(red)(3)#

Therefore, you can say that

#"Fe"_ 2"O"_ 3 -># iron(III) oxide

For calcium sulfide, keep in mind that calcium forms #2+# cations and sulfur forms #2-# anions, which means that you will have

#["Ca"]^(2+) * ["S"]^(2-) -> "Ca"_ 2"S"_ 2#

Therefore, you can say that

#"CaS " -># calcium sulfide

For sodium chloride, keep in mind that sodium forms #1+# carions and chlorine forms #1-# anions, which means that you will have

#["Na"]^(+) + ["Cl"]^(+) -> "Na"_ 1"Cl" _1#

Therefore, you can say that

#"NaCl " -># sodium chloride