NomenclatureNomenclature

Naming Compounds: Covalent•Name in order, the second element

gets the -ide ending•Each element has “prefix”- refers to

how many atoms of that element there are

Note: drop mono for first element

Ex: N2O4 dinitrogen tetraoxide

Ex: CO2 carbon dioxide

1 mono

2 di

3 tri

4 tetra

5 penta

6 hexa

7 hepta

8 octa

9 nona

10 deca

Practice

Give the corresponding name or formula•Carbon tetrafluoride

▫CF4

•P2O5

▫Diphosphorous pentoxide•N2O

▫Dinitrogen monoxide•CO

▫Carbon monoxide

•We can determine the formula of a compound by using the criss cross method using the ion charges

•E.g. what compound would form from Ca + S?Step 1 - write ion charge: Ca2+S2-

Step 2 - cross down ion charge: Ca2S2

Step 3 – reduce: CaS

Ionic Compounds: Formula

Practice!•Write the chemical formula for the following:

▫Al and Br AlBr3

▫K and S K2S

▫Mg and N Mg3N2

▫Be and O BeO

▫Cu and Cl CuCl or CuCl2

Ionic compounds: Naming•Metal (cation) first then non-metal•Non-metal ends in -ide.

▫ Example: sodium chloride

Give formulae & name: •Ca + I

▫ CaI2 calcium iodide

•O + Mg▫MgO magnesium oxide

•Na + S▫Na2S = sodium sulfide

Multivalent Metals• Multivalent (more than

one charge)• Often transition metals

• These you will need to know:

Iron Fe2+ Fe3+

Tin Sn2+ Sn4+

Lead Pb2+ Pb4+

Copper Cu1+ Cu2+

Multivalent Metals: Naming method 1•Stock System – the charge of the multivalent

ion is indicated as a Roman numeral after the name of the metal is written▫Ex: Fe2O3 iron (III) oxide

▫Ex: CuCl2 copper (II) chloride

Note: Metals in groups 1, 2, 3 or Ag+, Al3+, Zn2+

, exist with only one charge, therefore Roman numerals are not used when naming them.

Multivalent Metals: Naming method 2•Classical System – using latin stems and

one of two endings.• - ic bigger charge•- ous smaller charge

•Ex: Fe3+ = ferric Fe2+ = ferrousSn2+ = stannic Sn4+ = stannousPb2+ = plumbic Pb4+= plumbousCu1+ = cupric Cu2+ = cuprous

•Ex: Fe2O3 is ferric oxide

Polyatomic Ions• Polyatomic ions are a series, most often two

or more elements that are combined together with just one over all charge.

• They interact as a single unit▫To recognize if a compound has a polyatomic

ion: if there are at least three (3) elements in the compound.

• The positive ion is named first (check to see if it is a multivalent ion or is ammonium, NH4

1+). This followed by the named of the negative polyatomic ion

Polyatomic Ions to Know

•NO2- nitrite

•NO3- nitrate

•SO32- sulphite

•SO42- sulphate

•CO32- carbonate

•PO43- phosphate

•HCO3- hydrogen carbonate

•OH- hydroxide•NH4

+ ammonium

Tricks for Polyatomic Ions with Oxygen

ClO- hypochlorite - 2 oxygen

ClO2- chlorite - 1 oxygen

ClO3- chlorate standard

ClO4- perchlorate + 1 oxygen

•You can substitute other elements in for Cl

Practice!

Write the corresponding name or formula:•Ca(OH)2

▫Calcium hydroxide•Magnesium sulphite

▫MgSO3

•Ammonium hydroxide▫NH4OH

•Fe(NO3)2

▫Iron (II) Nitrate

Acids

•A compound that contains hydrogen and has special properties

•Must be in an aqueous state (aq) – dissolved in water

•2 types of acids1. Binary acids2. oxyacids

Naming Acids: Binary Acids

•Binary: H + non-metal▫ Ex: HCl

Binary acids: naming depends on state of acid• If it’s not aqueous: hydrogen + non-metal

HCl(g) = hydrogen chloride

• If it is aqueous: hydro + non-metal + ic acidHCl(aq) = hydrochloric acid

Ex: HBr(aq) is hydrobromic acid

Naming Acids: Oxyacids

• Oxyacids: H + polyatomic ion ▫ Ex: H2SO4

1.name the polyatomic ion2.Replace: ate ic,

ite ous1.add “acid” to the name

E.g. H2NO3 Nitrate NitricNitric acid

Practice•H3PO4(aq)

▫Phosphoric acid

•Hypochlorous acid▫HClO(aq)

•H2SO3(aq)

▫Sulphurous acid

•Carbonic Acid▫H2CO3(aq)

Hydrates• Some compounds contain H2O in their crystal lattice

structure. These compounds are called hydrates.

• The H2O can usually be removed if heated.• A dot () separates water

▫ Ex: CuSO4•5H2O• Name as usual, then a prefix + “hydrate” indicates

the # of H2O groups.▫ Ex: CuSO4•5H2O is copper(II) sulfate pentahydrate

sodium sulfate decahydrate nickel(II) sulfate hexahydrate

Na2CO3•H2O BaCl2•2H2O

Na2SO4•10H2O NiSO4•6H2O sodium carbonate monohydratebarium chloride dihydrate

Practice! Homework!!

•Nomenclature Worksheets