How do the names of the compounds, Carbon Tetrabromide and Magnesium Nitrate describe the chemical composition of each compound?

Question

In one paragraph preferably but any answer is fine.

Answer 1

Hi Kayla,

Chemical Nomenclature (AKA naming) is tough at the start, but once you learn the rules, it is pretty straight-forward! Every chemical name indicates 1) what elements are in the compound and 2) how many atoms of each element there is. This can then be written out as a chemical formula (Ex: Carbon Dioxide's chemical formula is CO₂), which describes the chemical composition (Ex: CO₂ has a chemical composition of 1 Carbon atom for every 2 Oxygen atoms).

Both of your examples use basic Ionic Nomenclature, so I've outlined those rules below and solved your individual problems. Let me know if you need anything else clarified.

Good luck!

Gigi

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Ionic Nomenclature Rules

1. Cation first, Anion second
2. The name of the cation is the same as the neutral element.
3. Exception: There are a few polyatomic cations that your teacher might expect you to know.
4. Very old nomenclature might have a prefix on the cation, but that is very unlikely.
5. The name of the anion will have a modified ending
6. If it's a monoatomic anion (has only 1 element), it will have the ending ("ide")
7. If it is a polyatomic anion (has 2 or more elements), it will have an "ate", "ite" or "ide" ending. (Your teacher probably gave you a list of polyatomic ions that you should know)
8. The anion will sometimes have a prefix that indicates quantity OR the cation might be followed by a roman numeral that indicates cation charge (which you can use to determine quantity)
9. If there is no prefix or roman numeral, you must determine and compare the charges to determine the balanced ratio of ions.
10. PRO TIP! Even if given a prefix, it's still a good idea to check that the charges balance

Prefixes: Mono - 1, Di - 2, Tri - 3, Tetra - 4, Penta - 5, Hexa - 6, Septa - 7, Octo - 8, Nona - 9, Deca - 10

Carbon Tetrabromide:

1. The Cation is Carbon, which is represented by the atomic symbol, C.
2. The Anion here is Bromide, which comes from the neutral element, Bromine, as indicated by the -"ide" ending. Bromine is represented by the atomic symbol, Br.
3. The "tetra" prefix means you have 4 Bromine atoms

That means that you have 1 C cation for every 4 Bromine anions, thus the chemical formula is CBr₄

Note: Carbon Tetrabromide is actually a covalent compound, however it is acceptable to name it with Ionic nomenclature (especially if you are in a HS chemistry class). It's Molecular (Covalent) name is Tetrabromomethane and it's modern IUPAC name is Carbon (IV) Bromide.

Magnesium Nitrate:

1. The Cation is Magnesium, which is represented by the atomic symbol, Mg.
2. The Anion here is Nitrate, a polyatomic ion, as indicated by the -"ate" ending. Nitrate is represented with the formula (NO₃)
3. Because you were not given a prefix, you must check to see if the cation's and anion's charges balance (AKA cancel to 0).
4. Mg has a +2 charge. (NO₃) has a -1 charge. This is NOT balanced

To balance the charges, you need 2 (NO₃) anions for every 1 Mg cation, thus the chemical formula is Mg(NO₃)₂