Naming CompoundsNaming Compounds

AmmoniumNitrate

1) Looking at the Periodic Table, determine the number of valence electrons likely for an element.

2) The element will combine with other atoms to reach stability, generally the octet rule states that is 8 electrons in the outer shell.

3) Match the elements so that the overall charge is neutral

Background: valences and formulas

Examples: a) Al,Br b) K,S c) Zn,O d) Mg,N e) C,Cl f) Cu,O

AlBr3 K2S ZnO Mg3N2 CCl4

CuO or Cu2O

Ionic compounds (metal with 1 valence)

Rules for naming• Anion ends in -ide. Example: sodium chloride• Metal comes 1st (not chlorine sodide)• Use the group valence for nonmetals• Do not capitalized unless starting a sentence

Give formulae & name: Ca + I, O + Mg, Na + S= Ca2+I1- = CaI2 = calcium iodide

= Mg2+O2- = MgO = magnesium oxide= Na1+S2-= Na2S = sodium sulfide

Multiple valence: Latin naming

• When the metal is in an ionic compound:• The metal is named with it’s Latin or English

root and ends in -ic or –ous to denote valenceCu1 is cuprous, E.g. Cu2 is

cupric• Lower Valence= ous, • Higher Valence= ic• Give formulas and Latin names for:

Cu2 + Cl = Cu2Cl1 = CuCl2 = cupric chlorideCo2 + Cl = Co2Cl1 = CoCl2 = cobaltous chloride

• For Latin naming: know rules, remember Hg is an exception –it is not named w/ its Latin name

Element(valence)

Englishname

Latin Name Highervalence

Lowervalence

Metals that have and use latin namesCu (1,2) Copper Cuprum Cupric CuprousFe (2,3) Iron Ferrum Ferric FerrousPb (2,4) Lead Plumbum Plumbic PlumbousSn (2,4) Tin Stannum Stannic Stannous

Metals that do not have latin namesCo (2,3) Cobalt - Cobaltic CobaltousCr (2,3) Chromium - Chromic ChromousMn (2,3) Manganese - Manganic Manganous

Metals that have latin names but use english rootHg (1,2) Mercury Hydrargyrum Mercuric Mercurous

• Name ends in -ide, positive/metal comes first• The valence of the metal is indicated using

roman numerals• E.g. Cu1 is copper(I), Cu2 is copper(II)• Numbers refer to valences not to #s of atoms

– Examples:

Cu2++Cl = CuCl2 = copper(II) chloride

Zn2++Cl = ZnCl2 = zinc chloride

Co2++Cl = CoCl2 = cobalt(II) chloride

Hg+S = Hg1S2 = Hg2S = mercury(I) sulfide

Hg+S = Hg2S2 = HgS = mercury(II) sulfide

Multiple valence: IUPAC/Stock naming

• Groups of atoms can also have valences• “Polyatomic ions” are groups of atoms that

interact as a single unit. • E.g. OH1, (SO4)2, (PO4)

Compounds containing polyatomic ions• So far we have given valences to single atoms

Li+ + O2- Li2O

• Naming compounds with polyatomic ions is similar to naming other ionic compounds

• Compounds with polyatomic ions have names ending in -ate or -ite

• Note that most are negative, except ammonium• Name: Ca(OH)2, CuSO4, NH4NO3, Co2(CO3)3

- calcium hydroxide

- copper(II) sulfate

- ammonium nitrate

- cobalt(III) carbonate

Ca(OH)2

CuSO4

NH4NO3

Co2(CO3)3

Compounds containing polyatomic ions

Naming covalent compounds• -ide ending, each element has “prefix”1 mono

2 di

3 tri

4 tetra

5 penta

6 hexa

7 hepta

8 octa

9 nona

10 deca

• prefix refers to # of atoms - not valenceN2O4 = dinitrogen tetroxide

• Exception: drop mono for first elementCO2 = carbon dioxide

• The first vowel is often dropped to avoid the combination of “ao” or “oo”.

CO = carbon monoxide

(monooxide)SO2= sulfur dioxide (doxide)

• Name: CCl4, P2O3, IF7

P4O10= tetraphosphorus decoxide

Write and name the following covalent compounds (IUPAC)

carbon tetrachloride

diphosporus trioxide

iodine heptafluoride

CCl4

P2O3

IF7

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