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Unit 4 - Nomenclature1. Naming Binary Compounds that contain a metal

and a nonmetal2. Naming Binary Compounds that contain only

nonmetals3. Naming Compounds that contain Polyatomic ions4. Naming Acids5. Writing Formulas from Names

Zumdahl pages 122-143

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Unit 4 - NomenclatureUpon completion of this unit, you should be able to do the following:

1. Name binary compounds of a metal and nonmetal2. Name binary compounds containing only

nonmetals3. Name common acids.4. Name compounds containing polyatomic ions5. Write the formula of a compound given its name

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Naming Binary CompoundsIt is important to understand how compounds are named to be able to communicate in the world of chemistry.

Binary compounds are composed of two elements. They can be divided into two classes: 1. Compounds that contain a metal and a non-

metal2. Compounds that contain two non-metals

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Naming Binary CompoundsWhen a metal such as sodium combines with a non-metal such as chlorine, the resulting compound contains ions. The metal loses one or more electrons to form a cation. The non-metal gains one or more electrons to form an anion. The resulting substance is called a binary ionic compound. These componds are named simply by using the names of the ions.

NaCl is sodium chlorideCaF2 is calcium fluoride

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Naming Binary Compounds

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Naming Binary CompoundsType I compounds – the metal forms only one cation.Type II compounds – the metal can form two (or more) cations that have different charges.

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Naming Binary Compounds

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Naming Binary CompoundsMore Type I Compound Examples

Compound Ions NameKI K+ , I- potassium chlorideCaS Ca2+ , S2- calcium sulfideLiBr Li +, Br- lithium bromideMgO Mg2+ , O2- magnesium oxide

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Naming Binary CompoundsNaming Type I Compounds Practice

a. LiF

b. AlCl3

c. MgI2

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Naming Binary CompoundsMany metals can form two (or more) cations that have different charges. For example, iron (Fe) can produce Fe2+ or Fe3+ cations. This means that if you saw the name iron chloride, you would not know if the compound was FeCl2 or FeCl3. Therefore we use Roman numerals to

Specify the charge on the cation. So FeCl2 is iron (II) chloride and FeCl3 is iron (III) chloride.

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Naming Binary CompoundsCommon Type II CationsFe2+ iron (II)Fe3+ iron (III)Cu+ copper (I)Cu2+ copper (II)Co2+ cobalt (II)Co3+ cobalt (III)Sn2+ tin (II)Sn4+ tin (IV)Pb2+ lead (II)Pb4+ lead (IV)

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Naming Binary Compounds

Naming Type II Compounds Practicea. CuClb. HgOc. Fe2O3

d. MnO2

e. PbCl4

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Naming Binary CompoundsBinary compounds that contain only nonmetals follow rules similar to those for naming binary ionic compounds.

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Naming Binary CompoundsType III Compound Examples

a. BF3 boron trifluoride

b. NO nitrogen monoxide

c. N2O5 dinitrogen pentoxide

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Naming Binary CompoundsNaming Type III Compounds Practice

a. PCl5

b. P4O6

c. SF6

d. SO3

e. SO2

f. N2O3

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Naming Polyatomic Ions•Polyatomic ions are charged entities composed of several atoms bound together.•See list on reverse side of periodic table handout•Naming is similar to binary compounds, but you must learn to recognize polyatomic ions•Name the cation first and then the anion. Use Roman numerals if the metal forms mutiple cations•For this class, you do not need to memorize a list of polyatomic ions

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Naming Polyatomic Ions

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Compounds with Polyatomic IonsExample:NH4C2H3O2

Recognize that NH4 + is the ammonium polyatomic cation

C2H3O2 - is the acetate polyatomic anion

The compound is ammonium acetate.

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Compounds with Polyatomic IonsPractice:Na2SO4

KH2PO4

Fe(NO3) 3

Mn(OH) 2

Na2SO 3

NH4ClO 3

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Compounds with Polyatomic IonsIn the list of polyatomic ions, notice that there are series of ions that contain a given element and different oxygen atoms. These are anions called oxyanions. When there are two members in such a series, the one with the smaller amount of oxygen is called –ite and the one with the larger amount of oxygen is called –ate. When there are more than two members of a series, hypo- (one less) and per- (one more) are used as prefixes.

ClO- hypochloriteClO2- chloriteClO3- chlorateClO4- perchlorate

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Naming Acids•When dissolved in water, certain molecules produce H+ ions. These substances are called acids.• An acid can have one or more H + ion. The rules for naming acids depend on whether the anion contains oxygen.•If the anion does not contain oxygen, the acid is named with the prefix hydro- and the suffix –ic attached to the root name for the element. HCl is hydrochloric acid.•When the anion contains oxygen and ends in –ate, the suffix for the acid becomes –ic. H2SO4 is sulfuric acid.•When the anion contains oxygen and ends in –its, the suffix for the acid becomes –ous. H2SO3 is sulfurous acid

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Naming AcidsCommon Acids

HCl hydrochloric acidH C2H3O2 acetic acid

H2SO4 sulfuric acid

HNO3nitric acid

H3PO4 phosphoric acid

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Writing Formulas from Names•You also need to be able to write the formula of a compound given the name. Again, you must be able to recognize polyatomic ions.

Example:Calcium hydroxideCalcium has a charge of +2. Hydroxide is OH with a charge of -1. Two hydroxide ions are required to balance the charge on calcium, so the formula is Ca(OH)2

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Writing Formulas from NamesPractice:Potassium hydroxideSodium carbonateCobalt (III) nitrateCalcium chlorideLead (IV) oxideDinitrogen pentoxideAmmonium perchlorate