Chapter 7Chapter 7

Part 1: Chemical Formulae Part 1: Chemical Formulae and Naming Ionic Compoundsand Naming Ionic Compounds

FormulaeFormulae

What does CClWhat does CCl44 really mean? really mean?– Is this ionic or covalent?Is this ionic or covalent?

Find the electronegativity of each element and Find the electronegativity of each element and use the table on page 162 to find out!use the table on page 162 to find out!

– How many atoms of each element are How many atoms of each element are involved?involved?

SymbolsSymbols What does the subscript mean?What does the subscript mean?

– What is it named?What is it named? Naming depends on whether the compound is Naming depends on whether the compound is

ionic or covalent.ionic or covalent.

FormulaeFormulae

How about AlHow about Al22(SO(SO44))33??– What do the parentheses mean?What do the parentheses mean?

Parentheses surround polyatomic ionsParentheses surround polyatomic ions The subscript on the parentheses means The subscript on the parentheses means

EVERYTHING inside is multipliedEVERYTHING inside is multiplied

– Does the compound have covalent or Does the compound have covalent or ionic bonds?ionic bonds?

– How many atoms are in this How many atoms are in this compound?compound?

Naming Ionic Naming Ionic CompoundsCompounds Monatomic IonsMonatomic Ions

– Ions formed from single atomsIons formed from single atoms– Charge determined by whether the Charge determined by whether the

atom gains or loses electrons (and atom gains or loses electrons (and how many)how many)

– Example: CaExample: Ca– Example: FExample: F

Naming Ionic Naming Ionic CompoundsCompounds Naming monatomic ionsNaming monatomic ions

– Ending of element’s name (usually –Ending of element’s name (usually –ine or –ium) droppedine or –ium) dropped

– Suffix –ide addedSuffix –ide added– Example: NaExample: Na++

– Example: SExample: S-2 -2

Naming Ionic Naming Ionic CompoundsCompounds Binary Ionic CompoundsBinary Ionic Compounds

– Composed of 2 different elements’ ionsComposed of 2 different elements’ ions Chemical formulaChemical formula

– Sum of charges of ions must equal Sum of charges of ions must equal zero!zero!

– Crossing over may be used to Crossing over may be used to determine subscriptsdetermine subscripts

– Example: Al bonded to SExample: Al bonded to S– Example: Mg bonded to IExample: Mg bonded to I

Naming Ionic Naming Ionic CompoundsCompounds Binary Ionic Compounds: Binary Ionic Compounds:

NomenclatureNomenclature Name of cation given first (no suffix)Name of cation given first (no suffix) Name of anion given with suffixName of anion given with suffix Usually number of ions not given, Usually number of ions not given,

since we know the chargessince we know the charges Example: AlExample: Al22SS33

Example: MgIExample: MgI22

Naming Ionic Naming Ionic CompoundsCompounds Sample Problem 7-1Sample Problem 7-1 Write formula and give name:Write formula and give name:

– Bonding of zinc and iodineBonding of zinc and iodine– Bonding of zinc and sulfurBonding of zinc and sulfur

Naming Ionic Naming Ionic CompoundsCompounds Stock SystemStock System Used for ions (usually cations) with more Used for ions (usually cations) with more

than one possible chargethan one possible charge– Is NOT used for ions that can have only one chargeIs NOT used for ions that can have only one charge

Roman numeral used to indicate chargeRoman numeral used to indicate charge Roman numeral is in parentheses directly Roman numeral is in parentheses directly

after ion’s nameafter ion’s name Example: FeExample: Fe+2 +2 ==

– Iron (II)Iron (II) Example: FeExample: Fe+3+3 = =

– Iron (III)Iron (III)

Naming Ionic Naming Ionic CompoundsCompounds Sample Problem 7-2Sample Problem 7-2 Write the formula and give the name Write the formula and give the name

for the compound formed by Crfor the compound formed by Cr+3+3 and and FF--..

Write the symbols with charges:Write the symbols with charges:– CrCr+3+3 F F-1-1 – Determine subscripts by using chargesDetermine subscripts by using charges

– Formula is CrFormula is Cr+3+3FF33-1-1

– Name: Chromium (III) fluorideName: Chromium (III) fluoride

Naming Ionic Naming Ionic CompoundsCompounds Polyatomic ions!Polyatomic ions! You MUST know the polyatomic You MUST know the polyatomic

ions!ions! Page 210:Page 210:

– AmmoniumAmmonium– AcetateAcetate– ChlorateChlorate– BicarbonateBicarbonate– Hydrogen sulfateHydrogen sulfate

Naming Ionic Naming Ionic CompoundsCompounds Polyatomic ions!Polyatomic ions! You MUST know the polyatomic You MUST know the polyatomic

ions!ions!– HydroxideHydroxide– NitrateNitrate– NitriteNitrite– PermanganatePermanganate– CarbonateCarbonate

Naming Ionic Naming Ionic CompoundsCompounds Polyatomic ions!Polyatomic ions! You MUST know the polyatomic You MUST know the polyatomic

ions!ions!– ChromateChromate– SulfateSulfate– SulfiteSulfite– PhosphatePhosphate

Naming Ionic Naming Ionic CompoundsCompounds Name of most common polyatomic ion Name of most common polyatomic ion

ends in –ateends in –ate– Example: ClOExample: ClO33

-1-1 is chlorate ion is chlorate ion Ion with one less oxygen ends in –iteIon with one less oxygen ends in –ite

– Example: ClOExample: ClO22-1-1 is chlorite ion is chlorite ion

Ion with less oxygen than –ite ion is Ion with less oxygen than –ite ion is called hypo – ion name –ite called hypo – ion name –ite – Example: ClOExample: ClO-1-1 is hypochlorite ion is hypochlorite ion

Ion with more oxygen than –ate ion is Ion with more oxygen than –ate ion is called per – ion name –ate called per – ion name –ate – Example: ClOExample: ClO44

-1-1 is perchlorate ion is perchlorate ion

Naming Ionic Naming Ionic CompoundsCompounds Sample problem 7-3Sample problem 7-3 Write the formula for tin (IV) sulfateWrite the formula for tin (IV) sulfate First write the symbolsFirst write the symbols

– SnSn+4+4 SO SO44-2-2

Check the charges: sum must be zeroCheck the charges: sum must be zero If you need more than one polyatomic If you need more than one polyatomic

ion, use parenthesesion, use parentheses– SnSn+4+4 ( SO ( SO44

-2 -2 ))22

Answer must use simplest whole number Answer must use simplest whole number ratio!ratio!

Ionic CompoundsIonic Compounds

Write the formula for:Write the formula for: Copper (II) nitrateCopper (II) nitrate Potassium iodidePotassium iodide Potassium permanganatePotassium permanganate Iron (III) nitrateIron (III) nitrate

Ionic CompoundsIonic Compounds

Name these compounds:Name these compounds: AgAg22SS

NaMnONaMnO44

Fe(ClO)Fe(ClO)22

NHNH44NONO33