Nomenclature Naming Compounds

Compounds with only two elements in any ratio Binary Compounds Compounds with only two elements in any ratio

Naming Binary Compounds

Ionic Compounds

Name positive element (cation) first with its normal name Name negative element (anion) last & change its ending to -ide

KCl CaCl2 Al2O3 Na2O

If the + element is not from columns I or II its ox # must be determined and written in roman numerals

FeO is Iron (II) Oxide Fe2O3 is Iron (III) Oxide CrO3 is Chromium (IV)Oxide

Determining the Charge Add up the oxidation numbers of all the negative elements The positive portion must balance out the negative portion Divide the positive portion by the metal subscript

CuCl Fe2O3 MnO2 CrO3

Molecule

A covalent compound that can exist as a separate unit Non-metals bond to form molecules

Naming Molecules or Covalent Compounds

Same rules as ionic compounds except: If two elements are from the same group, lower element is first. SO2 is sulfur dioxide use geometric prefixes to determine the # of each atom

Period 2 stopped here 9/8/06

Geometric Prefixes 1-mono 5-penta 2-di 6-hexa 3-tri 7-hepta 4-tetra etc

CO S2O3 N2H4 SO3

Deriving Formulas Write the symbol for each element Determine ox #s for each Determine lowest common multiple to balance the charge Apply subscripts

Polyatomic Ion

A group of atoms chemically combined that together have a charge

Naming Polyatomic Ions

Most are oxoanions A root element (most are non-metals) bound to oxygen

Name the root element Change the ending to -ate PO4-3 = phosphate Some are unusual

Polyatomic Ion Endings Maximum O = -ate 1 less than max O = -ite SO4-2 = sulfate SO3-2 = sulfite

Naming Ternary Compounds

Ternary Compounds Compounds containing more than two different elements Most contain polyatomic ions

Follow ionic rules for naming the compound Name the polyatomic ion as the positive or negative portion

CaCO3 K2SO4 Pb(NO3)2 MgSO3

Naming Acids

Binary acids become: Hydro _____ ic acids HCl - Hydrochloric acid

Ternary acids become: _____ ic acids or _____ ous acids H2SO4 - Sulfuric acid H2SO3 - Sulfurous acid

____ ic acids form from polyatomic ions ending with ___ ate ____ ous acids form from polyatomic ions ending with ___ ite

___ ide ions become: hydro ___ ic acids ___ ate ions become: ___ ic acids ___ ite ions become: ___ ous acids

Percent Composition by Mass

Determine the atomic mass of each element in the compound Determine the molecular mass of the compound by adding Divide each elemental mass by molecular mass Multiply by 100 %

MgCl2 Mg = 24.3 g/mole 2 Cl = 2 x 35.5 = 71.0 g/mole MgCl2 = total = 95.3 g/mole % Mg =24.3/95.3 x 100% % Cl = 71.0/95.3 x 100 %

Determine % Comp for Each: Fe2O3 C3H6O3 CuSO4*5H2O

Empirical Formula

Lowest whole number ratio of elements in a compound C6H12O6: EF = CH2O

Determining Empirical formulas from percent composition

Assume 100 g Change % directly to grams Use molar conversions to convert grams to moles Divide each molar amount by the smallest molar amount

Substance = 30 % O & 70 & Fe 30 % O --> 30 g O & 70 % Fe --> 70 g Fe 30/16 = 1.875 moles O 70 / 56 = 1.25 moles Fe 1.25/1.25 = 1 & 1.875/1.25 = 1.5 Ratio = 1.5 : 1 x 2 = 3 : 2 Empirical Formula Fe2O3

Find empirical for a compound with: 70.0 % Fe 30.0 % O

Find empirical for a compound with: 40 % Ca 12 % C 48 % O

Find empirical for a compound with: 40.0 % C 6.7 % H 53.3 % O

Molecular Formula

The actual whole number for each element in the compound

Molecular Formula C6H12O6 Empirical Formula CH2O

Solving MF from EF 1) Solve empirical mass 2) Divide EM into MM 3) Multiply EF by quotient

Name each of the following: KBr MgS BaF2 K3P K2O LiH Al2O3 H2S

Name each of the following: FeO Fe2O3

Name each of the following: CuO MnS PbO2 Cu2O CrCl2 MnF2 CrCl3 SnCl4

Name each of the following: SeO CS2 NO2 Cl2O N2O4 PCl3

Derive formulas for each: Cesium oxide Barium chloride Calcium phosphide Aluminum sulfide

Derive formulas for each: Lead(IV)oxide Copper(II)sulfide Manganese(VII)oxide Nickel(II)fluoride

Name each of the following: SO4-2 SO3-2 PO4-3 NO3-1 ClO4-1 ClO3-1 ClO2-1 ClO-1

Derive formulas for each: Chromate Arsenate Arsenite Bromite

Name each of the following: BaCO2 KNO2 CuClO3 Al2(SO4)3

Derive formulas for each: Potassium sulfate Lead(II)chromate Aluminum hydroxide Ammonium cyanide

Name each of the following: Cl2O SO2 N2O3 P2O5 CO2 CO SO3 N2H4

Derive formulas for each: Silicon dioxide phosphorus trichloride Sulfur hexafluoride Iodine trifluoride

Name each of the following: NH4Cl BaSO4 KC2H3O2 K2HPO3 KNO3 CuBrO Li2CO3 MgC2O4

Name each of the following: HCl H2SO4 H2S H3PO3 HNO3 HBrO H2CO3 HBrO4

Derive formulas for each: Chromic acid Hydroiodic acid Sulfurous acid Bromic acid

Name each of the following: KCl MnSO4 SO2 HI(aq) NaNO3 HClO H2CO3(aq) NH4BrO4

Chapter 3 General Define all the Key Terms on page 74

Nomenclature Work problems 43 – 56 On Pages 51 & 52