naming ions and naming and writing ionic compounds

Naming Ions and Naming and Writing Ionic Compounds

Monoatomic ions• cations lose valence electrons and therefore

are positively charged– transition metals form more than one cation

with different ionic charges– charge is determined from the # of

electrons lost• Fe2+ lost two electrons• Fe3+ lost three electrons

– naming• Stock system

– a Roman numeral is used to show the charge of the transition metal

» Fe2+ is iron(II) and Fe+3 is iron(III)

Naming Ions

Term DefinitionAg1+ silverCd2+ cadmiumZn2+ zincAu1+ gold(I)/aurousAu3+ gold(III)/auricCo2+ cobalt(II)/cobaltousCo3+ cobalt(III)/cobalticCr2+ chromium(II)/chromousCr3+ chromium(III)/chromicCu1+ copper(I)/cuprousCu2+ copper(II)/cupricFe2+ iron(II)/ferrousFe3+ iron(III)/ferricHg2

2+ mercury(I)/mercurousHg2+ mercury(II)/mercuricMn2+ manganese(II)Mn3+ manganese(III)Mn4+ manganese(IV)Ni2+ nickel(II)/nickelousNi3+ nickel(III)/nickelicPb2+ lead(II)/plumbousPb4+ lead(IV)/plumbicH1+ hydrogenH1- hydride

– anions gain valence electrons and therefore are negatively charged• change ending to -ide

Polyatomic ions• composed of more than one atom that

form a single unit/ion with a charge– most end with -ite or –ate

• the –ite ending indicates one less oxygen than the –ate ending

– ionic charge is the same for both

Naming ionic compounds• Binary Compounds

– cation is written first, followed by the anion with and –ide ending• Cs2O cesium oxide

• SrF2 strontium fluoride

• CuO copper(II) oxide– oxygen is always 2- and therefore copper will be 2+

• Cu2O copper(I) oxide– oxygen is 2- and therefore needed two copper

atoms with 1- charge

–SnF2 ?• fluorine is always 1- and therefore tin

will be 2+

–Stock system tin(II) fluoride–Traditional system stannous fluoride

–SnS2 ?• sulfur is always 2- and therefore tin will

be 4+

–Stock system tin(IV) sulfide–Traditional system stannic sulfide

Writing formulas for ionic compounds

• write symbol of cation and then anion

• add subscripts to balance the charges– calcium bromide

• Ca2+ and Br1- is CaBr2

– potassium sulfide

• K+1 and S2- is K2S

– iron(III) oxide

• Fe+3 and O2- is Fe2O3

crisscross method

• the ionic charge number of each ion is crossed over and becomes the subscript for the other ion

Formula to NameFe(NO3)3

Choose the correct name for the compound

1. Iron trinitrate

2. iron(I) nitrate

3. iron(III) nitrite

4. iron(III) nitrate

5. none of the abovenext

problemPolyatomic IonsPeriodic Chart

Name to Formulasodium chlorite

Choose the correct formula for the compound

1. NaCl

2. NaClO

3. NaClO2

4. Na(ClO)2

5. none of the above

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PrefixesPeriodic Chart