What is the chemical name for limestone, #"CaCO"_3# ?

1 Answer
Mar 1, 2017


Calcium carbonate.


The trick here is to realize that you're dealing with an ionic compound, which implies that the compound contains a cation and an anion.

As you know, ionic compounds are formed when a metal reacts with a non-metal, so start by identifying your metal.

In this case, calcium, #"Ca"# is the metal. Calcium is located in group 2 of the Periodic Table, which means that it forms #2+# cations. This means that you're dealing with the calcium cation, which looks like this

#"Ca"^(2+) -># the calcium cation

Now, the anion is actually a polyatomic ion made up of one carbon atom and three oxygen atoms. This polyatomic anion is called the carbonate anion and carries a #2-# charge.

#"CO"_3^(2-) -># the carbonate anion

When naming an ionic compound, we always start with the cation metal and end with the anion. In your case, you will have

#"CaCO"_3 -># calcium carbonate