Nomenclature

System of naming compounds

Molecular Nomenclature

Naming covalent compounds Based on a system of prefixes

One mono- six hexa- Two di- seven hepta- Three tri- eight octa- Four tetra- nine nona- Five penta- ten deca-

Examples of Molecular Names

CO2

CO P2O5

CCl4

Ion

Formed when electrons are added or removed from an atom

Gain electrons – become negative - Anion Lose electrons – become positive - Cation

Why Form Ions

Atoms gain or lose electrons to end up with the same number of electrons as the nearest noble gas

Predict the charges expected byO

Ba

Ion Generalizations

Metals generally form + charges, while non-metals form – charges

Ionic compounds tend to be composed of a metal combined with a non-metal

Molecular compounds usually are two non-metals

Polyatomic Ions

Atoms joined in a molecule but have a net charge– (SO4)2-

– NO3 -

Finding Formulas from Names

Calcium nitrate Copper (I) carbonate

Names from Formulas

AlCl3 K(NO3)

Al2O3

Fe3(PO4)2

Acid Names

Acids all start with an H For binary acids (H and one other element),

start with prefix hydro- and end with suffix –ic

Oxyacids

H, O and another element If anion has an –ate ending, give acid an –ic

ending If anion has an –ite ending, give acid an –ous

ending