Bires, 2007 Slide 1

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Chapter 7: Inorganic NomenclatureChapter 7: Inorganic Nomenclature• Inorganic

– branch of chemistry dealing with metals and nonmetals.

• Nomenclature– naming system used to identify

compounds.

• Binary compoundsBinary compounds– simplest compounds– contain only two elements.

• Remember: the cation is placed first, then the anion.

NaCl

2MgCl

LiBr

MgOcation anion

cation anion

Bires, 2007 Slide 2

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Naming Binary CompoundsNaming Binary Compounds• Begin with the positive ion

– the first element in the compound.

• The cation’s name first part of the compound’s name.

• The anion has its name truncated (shortened) and “–ide” is added.

• The correct name is then… Magnesium Chloride

2MgClMagnesium Chlorine

Name

Chloride

Bires, 2007 Slide 3

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Common Common anionsanions• O – oxygen, = “oxide”

• H – hydrogen, = “hydride”

• S – sulfur, = “sulfide”

• Cl – chlorine, = “chloride”

• F – fluorine, = “fluoride”

• I – iodine, = “iodide”

• N – nitrogen, = “nitride”

• C – carbon, = “carbide”

• Br – bromine, = “bromide”

• P – phosphorus, = “phosphide”

Some atoms can be positive or negative:

Carbon: -4 or +4

Nitrogen: -3 or +5

Sulfur: -2 or +6

Bires, 2007 Slide 4

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Multiple Multiple NonmetalNonmetal Anions Anions• When both elements are nonmetals.

– we add a latin-based prefix to the anion.• One anion: “mono-”

• Two anions: “di-”

• Three anions: “tri-”

• Four anions: “tetra-”

2COCarbon dioxide

3BFBoron trifluoride

4CClCarbon tetrachloride

Mono in front of a single anion is optional (older)

Carbon monoxide CO

Bires, 2007 Slide 5

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Special Special Cations Cations :: d-block metalsd-block metals• Transition metals (d-block):

– d-block electrons can migrate into the s and p orbitals.– metals can have several charges when bonding.– Use a Roman Numeral to show the cation’s charge:

• Fe2+ Co3+ Sn4+ Cr6+

• Iron(II) Cobalt(III) Tin(IV) Chromium(VI)• Identify the ions and charges on:• V4+ Cu2+ Tin (II) Nickel(IV)

D-block metals do not follow the octet rule when bonding

Bires, 2007 Slide 6

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• Oxidation number– charge that an atom would have when it bonds.

• The oxidation number of hydrogen in H2O is +1.

• The oxidation number of oxygen in H2O is -2.

• Rule 1: The total oxidation numbers of all the atoms in a compound must be zero. (NaCl)

• Rule 2: Oxidation of a free element is zero. (H2)

• Can you figure the oxidation numbers of the following atoms?

• Li+ Mg2+ CaS AgCl AlF3 O2

• +1 +2 -2 -1 +3 0Some elements can change their oxidation numbers in chemical reactions.

You need to predict the oxidation based on the location in the p-table

Common Oxidation States.mov

Bires, 2007 Slide 7

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Polyatomic ionsPolyatomic ions• Polyatomic ion:

– Ion composed of more than one element. (big)– stable units that bond like individual atoms.

• Polyatomic ions used in class are:

• NO3- “nitrate” charge of -1

• OH- “hydroxide” charge of -1• C2H3O2

- “acetate” charge of -1• SO4

2- “sulfate” charge of -2• CO3

2- “carbonate” charge of -2• PO4

3- “phosphate” charge of -3• NH4

+ “ammonium” charge of +1

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Naming With Polyatomic IonsNaming With Polyatomic Ions• Use the cation as

normal….

• Add the name of the polyatomic anion.

• Here, the compound is Copper (II)sulfate.

4CuSOCopper (II) sulfate

3LiNOLithium nitrate

23)(NOPbLead nitrate

Bires, 2007 Slide 9

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Nomenclature Practice…Nomenclature Practice…• Name the following:

• Identify the following compounds:

• Notice how the NO3- polyatomic is placed in ( )

2CaCl 4BaSO 3NaNO 2SrF )(4carefulCI

Calcium chloride

Barium sulfate

Sodium nitrate

Strontium fluoride

Carbon tetraiodide

Copper (II) nitrate(careful)

Potassium iodide

Boron trichloride

Lithium nitrate

3LiNO 23)(NOCuKI3BCl

Bires, 2007 Slide 10

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Empirical FormulaEmpirical Formula / / Molecular FormulaMolecular Formula• Molecular Formula

– shows the actual numbers of atoms in a molecule

• Empirical Formula– reduced form– shows only the ratio of atoms in a molecule:

( 1:2 or 1:2:1 )

• The empirical formula is useful in determining Percent Composition = mass % of one element in a compound.

42ON

2NO

6126 OHC

OCH 2

Calculate the % composition of oxygen in each of these compounds

% composition =

element mass (g) / empirical formula mass (g)

End of chapter 7