Naming IonsNaming Ions

What’s in a name?What’s in a name?

Romeo & JulietRomeo & Julietby William Shakespeareby William Shakespeare• “What’s in a name?What’s in a name? That which we call a

rose/By any other name would smell as sweet.”• In Spanish rosa• In Arabic warda• In Hindi julab• To truly know a culture you need to know its To truly know a culture you need to know its

language.language.• Same for chemistrySame for chemistry. You must know the

language of chemistry to understand its culture.

An ion An ion comprised comprised

of a single atomof a single atom(i.e. Ca(i.e. Ca2+2+, Cl, Cl--))

Monatomic Ion

An ion with a An ion with a POSITIVEPOSITIVEchargecharge

CATION

Positive/Negative ChargesPositive/Negative Charges

• Remember that the natural statenatural state of an atom is neutralneutral. The number of protons and electrons are equal.

• Ionic charge is based on the shape of the shape of the outer most orbitalouter most orbital dealing with the valance electrons. NOTNOT the balance of protons and electrons.

• This is counterintuitive.This is counterintuitive.

Key IdeaKey Idea

• When the metals in Groups 1A, 2A, & 3AGroups 1A, 2A, & 3A lose electronslose electrons, they form cationscations with positive chargespositive charges equal to their group number.

• To name the metals in this Group say the the name of the elementname of the element and addadd the word ionion (or cation) to the name.

• Ex. NaEx. Na++ = sodium ion = sodium ion

An ion with a An ion with a NEGATIVE NEGATIVE

chargecharge

ANION

Key IdeaKey Idea

• When the nonmetals in Groups 5A, 6A, & Groups 5A, 6A, & 7A7A gain electronsgain electrons, they form anionsanions with negative chargesnegative charges.

• The charge for any ion of this Group is determined by subtracting 8 from the subtracting 8 from the group numbergroup number.

• To name the nonmetals in this Group start with the stem of the element name and the stem of the element name and add add –ide–ide..

• Ex. PEx. P3-3- = phosphide ion = phosphide ion

Quick Chart: table 9.1 pg. 254Quick Chart: table 9.1 pg. 254

1A1A 2A2A 3A3A 4A4A 5A5A 6A6A 7A7A 8A8A

LiLi++ BeBe2+2+ NN3-3- OO2-2- FF--

NaNa++ MgMg2+2+ Al Al 3+3+ PP3-3- SS2-2- ClCl--

KK++ CaCa2+2+ AsAs3-3- SeSe2-2- BrBr--

RbRb++ SrSr2+2+ II--

CsCs++ BaBa2+2+

Quick Quiz: Monatomic IonsQuick Quiz: Monatomic Ions

• What are the names for each of the What are the names for each of the following?following?

• A) LiA) Li++

• B) MgB) Mg2+2+

• C) SrC) Sr2+2+

• D) OD) O2-2-

• E) AsE) As3-3-

• F) IF) I--

Quick Quiz: AnswersQuick Quiz: Answers

• What are the names for each of the What are the names for each of the following? What are there charges?following? What are there charges?

• A) LiA) Li++ lithium cationlithium cation

• B) MgB) Mg2+2+ magnesium cationmagnesium cation

• C) SrC) Sr2+2+ strontium cationstrontium cation

• D) OD) O2-2- oxide anionoxide anion

• E) AsE) As3-3- arsenide anionarsenide anion

• F) IF) I-- iodide anioniodide anion

Ions of Transition MetalsIons of Transition Metals• Includes Groups 1B-8BGroups 1B-8B• Form more than onemore than one cationcation with differentdifferent

charges.• Must be determined from the number of

electrons lostelectrons lost.• Two methods of naming:

– Stock nameStock name uses Roman numerals in parentheses. (Ex. Fe2+ = Iron (II) ion)

– Classical nameClassical name uses suffix –ous for lower ionic charge and –ic for higher ionic charge. (Ex. Fe2+ = Ferrous ion and Fe3+ = Ferric ion)

• See pg. 255 Table 9.2 for more examplesSee pg. 255 Table 9.2 for more examples

Transitional Metals with only 1 Transitional Metals with only 1 charge.charge.• AgAg++ silversilver

• CdCd2+2+ cadmiumcadmium

• ZnZn2+2+ zinczinc

Quick Quiz: Transitional metal ionsQuick Quiz: Transitional metal ions

• Give the name or the symbol for each of Give the name or the symbol for each of the following:the following:

A.A. CoCo2+2+

B.B. CoCo3+3+

C.C. Tin (II) ionTin (II) ionD.D. Tin (IV) ionTin (IV) ionE.E. Manganous ionManganous ionF.F. Manganic ionManganic ion

Quick Quiz: AnswersQuick Quiz: Answers

• Give the name or the symbol for each of Give the name or the symbol for each of the following:the following:

A.A. CoCo2+2+ Cobalt (II) ion or Cobaltous ionCobalt (II) ion or Cobaltous ionB.B. CoCo3+3+ Cobalt (III) ion or Cobaltic ionCobalt (III) ion or Cobaltic ionC.C. Tin (II) ionTin (II) ionSnSn2+2+

D.D. Tin (IV) ionTin (IV) ion SnSn4+4+

E.E. Manganous ionManganous ion MnMn2+2+

F.F. Manganic ionManganic ion MnMn3+3+

An ionAn ionmade up of made up of two or moretwo or more

atomsatoms(i.e. SO(i.e. SO44

2-2-))

Polyatomic Ion

Key IdeaKey Idea

• The names of most polyatomic anionsanions end in end in –ite–ite or or –ate–ate.

• The positively charged ammonium cationcation ends in –ium.–ium.

• CNCN- - & OH& OH-- end in –ide.

EndingsEndings

Notice that the Notice that the charges don’t changecharges don’t change. . Also, prefixes and endings do Also, prefixes and endings do NOTNOT tell you the actual tell you the actual number of oxygen atoms.number of oxygen atoms.

• ate = base unitate = base unit• Ex. Sulfate SOEx. Sulfate SO44

-2-2 • per = add one oxygen

• Ex. Persulfate SO5-2

• ite = subtract one oxygen • Ex. Sulfite SO3

-2

MemorizeMemorize

• If you remember the previous rule If you remember the previous rule then all you have to memorize is then all you have to memorize is

the the -ate-ate endings only. endings only.

substance substance formed formed

when two ions when two ions bond togetherbond together

Ionic CompoundsIonic Compounds

How do you How do you write ionic write ionic

compounds?compounds?

Kris Kross Method!Kris Kross Method!

CaCa33AsAs22

CaCa2+2+AsAs3-3-

Just kris kross the Just kris kross the positive and the positive and the negative chargesnegative charges(LCM)(LCM)

NaClNaClPbPb4+4+OO2-2- PbOPbO22

NaNa1+1+ClCl1-1-

Which charge Which charge ALWAYS ALWAYS

comes first?comes first?POSITIVE!!POSITIVE!!!!

How to How to Name Ionic Name Ionic FormulasFormulas

Compound made Compound made up of only two up of only two

elementselements

Binary CompoundBinary Compound

1)1) Write the name Write the name of the cationof the cation

Naming Binary Formulas:Naming Binary Formulas:

2) Write the name of the anion (-ide ending)

1)1) Write the name Write the name

of the cationof the cation

Naming Other Ionic Naming Other Ionic Compounds:Compounds:

2) Write the name of the anion (that’s it!)

Don’t be confusedDon’t be confused

+ and +1

both mean the same thing.

Know the differenceKnow the difference

• Oxidation state and Charge

• Li+ and NO2-1

Work in groups on the practice problems sheet for section 9.1 & 9.2Work in groups on the practice problems sheet for section 9.1 & 9.2

Naming Binary Molecular Naming Binary Molecular CompoundsCompounds• Defined as a compound composed of two

nonmetals.• The prefix in the name tells how many atoms of

each element are present in each molecule of the compound.

• The names of all binary molecular compounds end in –ide.

• The vowel at the end of a prefix is dropped when the name of the element begins with a vowel. (Ex. Carbon monoxide, not carbon monooxide.)

Quick Chart: Binary Molecular Quick Chart: Binary Molecular CompoundsCompounds

PrefixPrefix MonoMono DiDi TriTri TetraTetra PentaPenta HexaHexa HeptaHepta OctaOcta NonaNona DecaDeca

NumberNumber 1 2 3 4 5 6 7 8 9 10

Table 9.4 pg. 269Table 9.4 pg. 269

Guidelines for NamingGuidelines for Naming• Confirm Confirm that the compound is a binary

molecualr compound.• The name must identify the elements in the

molecule and indicate the number of each atom of each element.

• Name the elements in the order listed in the formula.

• Use prefixes to indicate the number of each kind of atom.

• If just one atom of the first element is in the formula omit the prefix mono.

• Add –ide to the suffix of the second element.

Name the following:Name the following:• N2O• SF6

• Cl2O8

• CS2

• AsCl5• PBr5

• P4S3

• S2Cl2• IF7

Answers to the following:Answers to the following:

• N2O = dinitrogen monoxidedinitrogen monoxide• SF6 = sulfur hexafluoridesulfur hexafluoride• Cl2O8 = dichlorine octoxidedichlorine octoxide• CS2 = carbon disulfidecarbon disulfide• AsCl5 = arsenic pentachloridearsenic pentachloride• PBr5 = phosphorus pentabromidephosphorus pentabromide• P4S3 = tetraphosphorus trisulfidetetraphosphorus trisulfide• S2Cl2 = disulfur dichloridedisulfur dichloride• IF7 = iodine heptafluorideiodine heptafluoride

Give the formula for the following:Give the formula for the following:

• Phosphorous pentachloride

• carbon tetracholoride

• Nitrogen dioxide

• Dinitrogen difluoride

• Tetraphosphorous hexoxide

• Xenon difluoride

• Silicon dioxide

• Dicholorine heptoxide

Answers for the following:Answers for the following:

• Phosphorous pentachloride PClPCl55

• carbon tetrachloride CClCCl44

• Nitrogen dioxide NONO22

• Dinitrogen difluoride NN22FF22

• Tetraphosphorous hexoxide PP44OO66

• Xenon difluoride XeFXeF22

• Silicon dioxide SiOSiO22

• Dicholorine heptoxide ClCl22OO77