Nomenclature: Naming Compounds

Ionic Compounds

Formed when electrons are transferred from the less electronegative atom (Na) to the more electronegative atom (Cl).

Na e-1 Cl

to give

Na+1 and Cl1

thusNaCl

Electronegativity

Tendency for atoms to attract electrons Metals have low electronegativity Metals lose electrons to form ions

(Na+1) Non-metals have high electronegativity Non-metals gain electrons to form ions

(Cl1)

Ionic Compounds (NaCl)

Formed between metals and non-metals

Use element name of the metal (sodium) Add –ide to root name of non-metal

(chloride)

We have: sodium chloride

Predicting Charges on Monatomic IonsKNOW THESE !!!!

+1 +2 -3 -2 -1 0

Cd+2

The –ides Of Compound Names Fluorine

Chlorine

Bromine

Iodine Oxygen Sulfur Carbon Nitrogen

Phosphorus

FluorideChlorideBromideIodideOxideSulfideCarbideNitridePhosphide

Name – ide Compounds KCl Na2O CaS MgBr2 ZnCl2 Ag2S Al2O3 CaC2 K3N

Potassium chlorideSodium oxideCalcium sulfideMagnesium bromideZinc chlorideSilver sulfideAluminum oxideCalcium carbidePotassium nitride

Polyatomic ions

Special naturally ocurring ions that have their own names- they end in -ite, -ate or other

Names of Polyatomic Ions with Oxygen Polyatomic ions

usually contain oxygen in addition to another element. 

Normally they have a negative charge. 

They end in either "ate" or "ite" depending on the number of oxygen atoms present.

ClO- hypochlorite

ClO2- chlorite

ClO3- chlorate

ClO4- perchlorate

NO2- Nitrite 

NO3- Nitrate 

PO33- phosphite 

PO43- phosphate 

SO32-

SO42-

sulfite sulfate 

Name –ate Compounds

KNO3 CaCO3 AlPO4 MgSO4 Ca(NO3)2 K3PO4 Al2(SO4)3 Mg3(PO4)2

Potassium nitrate

Calcium carbonate

Aluminum phosphate

Magnesium sulfate

Calcium nitrate

Potassium phosphate

Aluminum sulfate

Magnesium phosphate

Some Other Polyatomics

OH1

NH4+1

CN1

HCO31

HSO41

Hydroxide

Ammonium

Cyanide

Bicarbonate

Bisulfate

Name Some Other Polyatomics

KOH Al(OH)3 NH4Cl (NH4)2SO4 KCN HCN NaHCO3 KHSO4

Potassium hydroxide

Aluminum hydroxide

Ammonium chloride

Ammonium sulfate

Potassium cyanide

Hydrogen cyanide

Sodium bicarbonate

Potassium bisulfate

Elements with Multiple Cations

When an element can form more than one cation a Roman numeral is used to distinguish the oxidation state of the compound.Iron, Tin, Lead, Copper, and are common elements with more than one cation. Examples

1. PbSO4  =  lead (II) sulfate   This compound is formed from Pb2+ and  SO4

2-

2. Pb(SO4)2 =  lead (IV) sulfate   This compound is formed from Pb4+ and  SO4

2-

3. Fe(OH)2  =  iron (II) hydroxide   This compound is formed from Fe2+ and 

OH- 4. Fe(OH)3  =  iron (III)  hydroxide    This compound is

formed from Fe3+ and  OH-

Naming Covalent Compounds

Chemistry

Dr. May

Covalent Compounds

Formed when electrons are shared between two atoms having similar electronegativities

Formed between two non-metals such as sulfur (S) and oxygen (O) or carbon (C) and oxygen.

SO SO2 SO3 SO4

CO CO2

Naming Guidelines – PBr5

Less electronegative element comes first Name of element (phosphorus) Prefix needed if more than one atom More electronegative element comes next Prefix needed, even if 1 (mono) Root name plus –ide (pentabromide) PBr5 is phosphorus pentabromide

Possible Prefixes One is Two is Three is Four is Five is Six is Seven is Eight is Nine is Ten is

Mono-

Di-

Tri-

Tetra-

Penta-

Hexa-

Hepta-

Octa-

Nona-

Deca-

Name Covalent Compounds

CO CO2

SO2

SO4

SF6

NI3

P2O5

CCl4

Carbon monoxide

Carbon dioxide

Sulfur dioxide

Sulfur tetraoxide

Sulfur hexafluoride

Nitrogen triiodide

Diphosphorus pentoxide

Carbon tetrachloride