P. Sci.Unit 9Chemical CompoundsChapter 6

Part 2

Compound Names and Formulas

Binary Compounds

• Most of the compounds that you will have to name will have only 2 elements (called binary – bi meaning 2)

or an element and a polyatomic ion.

NaCl

CaCl2

P2O5

NaNO3

Al(ClO3)3

NaClCaCl2P2O5

NaNO3

Al(ClO3)3

Naming Compounds

• First you have to identify what type of compound it is :–Ionic – metal and non-metal.

–Covalent – two non-metals

–Polyatomic - both

NaClN2O4

CaCO3

Ionic Compounds

1.Write the name of the metal (cations = + ion)

Examples:Na = SodiumCa = CalciumAl = Aluminum

Ionic compounds cont.

2.Write the name of the non-metal (anion = - ion) but change the ending to “ide”.

Examples: Chlorine – ChlorideFluorine – FluorideOxygen – OxideSulfur – SulfidePhosphorus – PhosphideIodine - Iodide

Examples

• NaCl = Sodium chloride

• CaI2 = Calcium iodide

• CsBr = Cesium bromide

• Al2O3 = Aluminum OxideFor ionic compounds – pay no attention to the subscripts.

Now you try

• Name the following ionic compounds.–LiF =

–MgO =

–SrCl =

–K2S =

–Ca3N2 =

Answers

–LiF = Lithium fluoride

–MgO = Magnesium oxide

–SrCl = Strontium chloride

–K2S = Potassium sulfide

–Ca3N2 = Calcium Nitride

Covalent Compounds

1.First Name

a)If there is only one atom of this element, just write the name of the element.

Example: N = Nitrogen

C = CarbonP = Phosphorus

Covalent compounds cont.

1.First Name cont.b)If there is more than one

atom of the element, write the name of the element with the pre-fix that tells how many atoms are there.

Pre-fixes

1 – mono 6 – hexa

2 – di 7 – hepta

3 – tri 8 – octa

4 – tetra 9 – nona

5 – penta 10 – deca

Examples: H2 – di-hydrogen

C3 – tri-carbon

Br4 – tetra-bromine

Covalent compounds cont.

2.Second Name – Always has a prefix.

a)Always starts with a prefix that tells how many atoms are there. (even if there is only one)

2.Second Name cont.b) ends in “ide”

Covalent compounds cont.

Examples :CO – carbon monoxideCO2 – carbon dioxideCO3 – carbon trioxide

Now you try

• Name the following covalent compounds.– NO2 =

–PBr3 =

– AsCl =

–H2O =

–H2O2 =

Answers

– NO2 = Nitrogen dioxide

–PBr3 = Phosphorus tribromide

– AsCl = Arsenic monochloride

–H2O = Di-hydrogen monoxide

–H2O2 = Di-hydrogen dioxide

Polyatomic Ions

• Compounds with both ionic and covalent bonds.

• Acts the same as any other ion.

Polyatomic ions cont.

• Examples:

–Ammonium NH4+

–Hydroxide OH-

–Sulfate SO4+2

–Carbonate CO3-2

Polyatomic compounds

• Follow step one for ionic compounds. (Write the name of the metal)

• Write the name of the polyatomic ion (do not change to “ide”)

Examples: NaNO3 = Sodium nitrateAl(ClO3)3 = Aluminum chlorate