Nomenclature We can determine the formula of a compound by completing Lewis diagrams or via the criss cross method By knowing the valence of elements.

NomenclatureNomenclature

• We can determine the formula of a compound by completing Lewis diagrams or via the criss cross method

• By knowing the valence of elements you can determine the formula of compounds

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

Step 2 - cross down valences: Ca2S2

Step 3 – reduce: CaS

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 compoundsRules for naming

• Names end in -ide. Example: sodium chloride• Metal (cation) comes 1st (not chlorine sodide)• Do not capitalize (unless it’s the start of a sentence)

Give formulae & name: Ca + I, O + Mg, Na + S= Ca2I1 = CaI2 = calcium iodide

= Mg2O2 = MgO = magnesium oxide= Na1S2 = Na2S = sodium sulfide

Multiple valence: Latin naming• When the metal in an ionic compound is multivalent

there are 2 methods: Latin or IUPAC• As before, the name ends in -ide & metal is first• The metal is named with it’s Latin or English root and

ends in -ic or –ous to denote valence

• E.g. Cu1 is cuprous, E.g. Cu2 is cupric• Lower = ous, Higher = ic

• Give formulas and Latin names for:Cu2+ + Cl- = CuCl2 = cupric chloride

= copper (II) chloride (IUPAC)Cu+ + Cl = CuCl = cuprous chloride

= copper (I) chloride

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 in brackets

using roman numerals• E.g. Cu1 is copper(I), Cu2 is copper(II)• Numbers refer to valences not to #s of atoms• Try: • Cu2+Cl, Zn2 + Cl, Co2+Cl, Hg+S (do both)

Cu2+Cl = Cu2Cl1 = CuCl2 = copper(II) chloride

Zn2+Cl = Zn2Cl1 = ZnCl2 = zinc chloride

Co2+Cl = Co2Cl1 = CoCl2 = cobalt(II) chloride

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

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

Multiple valence: IUPAC 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. Ba3(PO4)2 =

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

Li + O Li1O2 Li2O

barium phosphate

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

• You should note that compounds with polyatomic ions have names ending in -ate or -ite not -ide

• 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

Working backwards: name to formula• It’s possible to determine a formula from a name• E.g. What is the formula of sodium oxide?• To get the answer, first write the valences:

Na1O2 Na2O• What is the formula of copper(II) oxide?

Cu2O2 Cu2O2 CuO• For covalent compounds, simply use the prefixes to

tell you the number of each element:• What is the formula for dinitrogen trioxide?

N2O3

• Give formulae for: lithium sulfide, dinitrogen monoxide, lead(IV) sulfate

Write and name the following covalent compounds (IUPAC)

Li1S2 Li2S

N2O

Pb4(SO4)2 Pb2(SO4)4 Pb(SO4)2

lithium sulfide

dinitrogen monoxide

lead(IV) sulfate

1. Name each according to IUPAC rules: a) ZnS, b) FeCl3, c) CaCO3, d) P2O5, e) NaCN, f) N2F2, g) MgHPO4, h) Cu(BrO3)2, i) K2O, j) BF3

2. Give the valence of a) Fe in FeO, b) Mn in MnO2

3. Write formulas for: a) sodium oxide, b) potassium iodide, c) plumbic sulfide, d) mercury(I) oxide, e) ferrous oxide, f) iron(II) phosphate, g) copper(II) fluoride, h) dichlorine monoxide, i) silver sulfide, j) magnesium nitride, k)

aluminum hypochlorite, l) iodine pentafluoride, m) calcium chromate, n) diphosphorus pentasulfide

Assignment

Answers – 1, 2a) zinc sulfide b) iron(III) chloridec) calcium carbonated) diphosporus pentoxidee) sodium cyanidef) dinitrogen difluorideg) magnesium hydrogen phosphateh) copper(II) bromatei) potassium oxidej) boron trifluoride

2 a) 2 b) 4

Answers – 3

a) Na2O

b) KI

c) PbS2

d) Hg2O

e) FeO

f) Fe3(PO4)2

g) CuF2

h) Cl2O

i) Ag2S

j) Mg3N2

k) Al(ClO)3

l) IF5

m) CaCrO4

n) P2S5

• Bases contain an OH group• C6H12O6 does not have an OH group• If an OH group is present it will be clearly indicated:

e.g. NaOH, Ca(OH)2 • Also notice that bases have a metal (or positive ion

such as NH4+ at their beginning)

• Bases are named like other ionic compounds:• +ve is named first, followed by the polyatomic ion

Naming Bases

- calcium hydroxide - copper(I) hydroxide

- Al(OH)3

- NH4OH

Ca(OH)2

CuOHaluminum hydroxide

ammonium hydroxide

• All acids start with H (e.g. HCl, H2SO4)• 2 acids types exist: binary acids and oxyacids

Binary: H + non-metal. E.g. HClOxy: H + polyatomic ion. E.g. H2SO4

• Each have different naming rules.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 acid

HCl(aq) = hydrochloric acid (aqueous hydrogen chloride)

Naming Acids: Binary acids

HBr(s) HI(aq)H2S(aq) H2S(g)

hydrogen bromide hydroiodic acidhydrogen sulfidehydrosulfuric acid

• Naming does not depend on the state (aq)• 1) name the polyatomic ion

2) replace ate with ic, ite with ous3) change non-metal root for pronunciation4) add “acid” to the name

E.g. H2SO3

Naming Acids: Oxyacids

HNO2 hypochlorous acid

H3PO4(aq) carbonic acid

1) sulphite, 2) sulphous,

3) sulphurous, 4) sulphurous acid

Naming Acids: Oxyacids

HNO2 hypochlorous acid

H3PO4(aq) carbonic acid- nitrous acid - HClO

- phosphoric acid - H2CO3

a) chloric acidb) hydrosulfuric acidc) hydrobromic acidd) phosphorous acide) iodic acidf) HCl(g)g) HCl(aq)h) H2SO4(s)

i) H2SO4(aq)

j) HClO2

k) HF(aq)

Assignment: give formula or namea) HClO3

b) H2S(aq)

c) HBr(aq)d) H3PO3

e) HIO3

f) hydrogen chlorideg) hydrochloric acidh) sulfuric acidi) sulfuric acidj) chlorous acidk) hydrofluoric acid

• Some compounds contain H2O in their structure. These compounds are called hydrates.

• This is different from (aq) because the H2O is part of the molecule (not just surrounding it).

• The H2O can usually be removed if heated.• A dot separates water: e.g. CuSO4•5H2O is

copper(II) sulfate pentahydrate.• A greek prefix indicates the # of H2O groups.

Hydrates

sodium sulfate decahydrate nickel(II) sulfate hexahydrate

Na2CO3•H2O BaCl2•2H2O

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