Nomenclature of Ionic compounds
Nomenclature is the devising or choosing the names of things, in Chemistry it is used for naming compounds. In this case the focus will be ionic compounds. ionic compounds are formed when a metal gives up its valence electrons to a non-metal, in less words if a compound contains a meta and a non-metal it is an ionic compound. The elements in blue are the metals, the yellow are the non-metals, and pink are called metalloids.
when it comes to naming ionic compounds there are some rules to be followed:
- The metal ion's name DOES NOT change.
- The non-metals name ends in IDE.
METALS AND NON-METALS
AlCl3 = Aluminum chloride
KF = Potassium flouride
MgO = Magnesuim oxide
**notice that the subscripts do not affect the way the compounds are named**
POLYATOMIC IONS
Metals also bond with a special type of ions called Polyatomic ions which simply consist of two or more atoms with one overall charge, the same rules apply for naming the compound of metals and polyatomic ions. The table below shows a list of the most common ions, their names, formula and charges.
POLYATOMIC ION |
NAME |
OH-1 |
Hydroxide |
SO4-2 |
Sulfate |
PO4-3 |
Phosphate |
NO3-1 |
Nitrate |
CO3-2 |
Carbonate |
ClO3-1 |
Chlorate |
NH4+1 |
Ammonium |
Let's take a look at some examples naming compounds with polyatomic ions in them:
- Na2CO3 = Sodium carbonate
- KNO3 = Potassium nitrate
- NaNO3= Sodium nitrate
TRANSITION METALS
Ionic compounds are also formed with transition metals,which are the elements with atomic numbers 21-30, 39-48 and 57-80, but there is one difference that can make naming these compounds a bit difficult. Because transition metal can assume more than one charge, it has to be specified which one is involved, by using Roman numerals. The Roman numerals will help determine the charge of the element present in the compound. Here's a chart to help understand this better:
Roman Numeral |
Charge |
I |
+1 |
II |
+2 |
III |
+3 |
IV |
+4 |
V |
+5 |
VI |
+6 |
Now let's see some examples:
- MnO = Manganese (II) oxide
- Cu2O = Copper (I) oxide
VIDEO
For further help on this topic take a look at this video:
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