Chapter 7Chapter 7Nomenclature

CHM130

GCC

NomenclatureNomenclature

• We will be presenting this chapter a bit different than the text book does. The information is the same, so reading the text is still a good idea. But take an especially careful look at the online notes for this chapter. Good luck!

TermsTerms• Ionic compound = metal + nonmetals

• Covalent compound = nonmetals only, (aka molecular)

• Monoatomic ion = one atom w/charge– Na+, Cl-, Ca2+

• Polyatomic ion = two or more atoms w/charge (listed on your Periodic Table – become familiar with them)– PO4

3-, OH-, CO32-

Element NamesElement Names

• Know the names for elements 1-20 AND– Barium Ba Silver Ag– Cobalt Co Gold Au– Iodine I Zinc Zn– Copper Cu Tin Sn– Iron Fe Strontium Sr– Lead Pb Nickel Ni– Mercury Hg Bromine Br

Ionic CompoundsIonic Compounds

• We will begin by learning formulas and names for ionic compounds

• Remember that ionic compounds are made of ions, and ions have a charge

• The sum of the charges must = zero

Oxidation StatesOxidation States

• Is a fancy name for charge• All elements have a charge of zero when

they are alone (elemental state)• Elements have a charge when they have

lost or gained electrons– Some elements have a fixed charge – only

one possibility– Other elements have variable charge –

several possibilities

CationsCations• Metals lose electrons to be cations (+)

• Charges (learn these)– Column IA is always +1 (alkali metals)– Column IIA is always +2 (alkaline earth metals)– Column IIIA is often +3 (Al always)– Zn and Cd always +2– Silver always +1– Other metals can vary from +1 to +9 so use

Roman Numeral to tell the difference like Cu+2 is copper(II), Fe+3 is iron(III), Pb+4 is lead(IV)

AnionsAnions• Nonmetals gain electrons to be anions (-)• Charges (learn these)

– Column 5 is –3 usually– Column 6 is –2 usually– Column 7 is –1 usually (F always)– Column 8 is 0 Why???

Noble gases are already happy with 8 outer valence electrons (He has 2) so don’t need to form bonds – they don’t want to gain or lose electrons!!!

7.3 Polyatomic Ions7.3 Polyatomic Ions

• Check out information on your periodic table

• Keep these atoms together as a group, think of them as a group, a single entity

Formulas of Ionic CompoundsFormulas of Ionic Compounds• Compounds MUST be neutral• Need enough cations and anions to = zero• Combine Na and N: Na is +1 and N is –3 so need

three Na’s for one N so Na3N is the formula • What is the formula?

– Na and S– Mg and O– K and Br– Ca and N– Al and Cl– Zn and I – Cu(II) and O

Na2S

MgO

KBr

Ca3N2

AlCl3

ZnI2

CuO

Formulas with Polyatomic IonsFormulas with Polyatomic Ions

• What is the Formula?– Mg and OH-

– K and PO43-

– Ag and SO42-

– Ca and NO3-

– Cu(II) and CO32-

– Pb(IV) and O

Mg(OH)2

K3PO4

Ag2SO4

Ca(NO3)2

CuCO3

PbO2

Naming Ionic CompoundsNaming Ionic Compounds

• Now that you can write ionic compound formulas, we need to learn their names

• The name depends on whether the metal has a fixed or variable charge

• For a fixed charge metal, like Na, we KNOW the charge so don’t use Roman numerals

• For a variable charge metal, like Cu, we don’t know the charge so we do use Roman numerals

• Check it out…

Fixed charge metal ionic compoundFixed charge metal ionic compound• Metal name + nonmetal + “ide”

– NaCl sodium chloride

What is the name?– KBr– MgO

– CaF2

– Li2S

– AgCl

– Note the ionic name does NOT indicate how many atoms there are

Potassium bromide

Magnesium oxide

Calcium fluoride

Lithium sulfide

Silver Chloride

Names with Polyatomic IonsNames with Polyatomic Ions

• Do NOT change the polyatomic ion name– NaNO3 sodium nitrate

What is the name?

– K3PO4

– Ca(OH)2

– ZnSO4

Potassium phosphate

Calcium hydroxide

Zinc sulfate

Variable charge Metal Ionic CompoundVariable charge Metal Ionic Compound

• Metal name (Roman #) + nonmetal + “ide”• YOU must figure out charge on Trans metal

– CuCl2 copper(II) chloride (Cu must be +2 since Cl is –1 and there are two of them)

What is the name?

– PbO2

– FeBr3

– CoSO4

– HgNO3

– CoN

Lead(IV) oxide

Iron(III) bromide

Cobalt(II) sulfate

Mercury(I) nitrate

Cobalt(III) nitride

• YOU must figure out the formula AND the name for ionic compounds.

• Name only for covalent compounds (Why? They don’t have ions so you can’t add to zero)

• Example: K and O– You figure out formula:– You figure out name:

K2OPotassium oxide

Covalent / Molecular CompoundsCovalent / Molecular Compounds• Compounds with only nonmetals• These are NOT ions, so no charges• Use prefixes

– mono -penta– di -hexa– tri -hepta– tetra -octa

• Prefix + nonmetal name + prefix + 2nd nonmetal name + “ide”

• Don’t use mono for the 1st nonmetal

ExamplesExamples

• CO2 is carbon dioxide

What is the name?

• CO

• P2O5

• PF3

• IF7

Carbon monoxide

Diphosphorus pentoxide

Phosphorus trifluoride

Iodine heptafluoride

Given the formula, write the Given the formula, write the name and vice versaname and vice versa

• Br3O8

• P4S7

• SO3

• Iodine hexafluoride

• Dichlorine pentaoxide

• P2I4

Tribromine octaoxide

Tetraphosphorus heptasulfide

Sulfur trioxide

IF6

Cl2O5

Diphosphorus tetraiodide

Reminders• Prefixes are ONLY with covalent

compounds

• Roman Numerals are ONLY with variable charged metal compounds

• Polyatomic ions NEVER change their name

AcidsAcids• Compounds that lower pH in water• Have H+ ions in them• Dissolved in water = (aq)• You should memorize these 6 acids

– HCl(aq) hydrochloric acid– HF(aq) hydrofluoric acid

– H2SO4 (aq) sulfuric acid

– H3PO4 (aq) phosphoric acid

– HNO3 (aq) nitric acid

– H2CO3 (aq) carbonic acid

What the heck is (aq)?

Write the formula or name for Write the formula or name for each – you have 3 minutes!each – you have 3 minutes!

• BaCl2• NO2

• Fe3(PO4)2

• Diiodine tetraoxide

• Silver sulfate

• Nickel(III) sulfide

Barium chloride

Nitrogen dioxide

Iron(II) phosphate

I2O4

Ag2SO4

Ni2S3

• Do the chapter 7 worksheet posted on this practice problems web page

• Seriously – JUST DO IT • http://web.gccaz.edu/~ksmith8/rev130.htm

Self TestSelf TestPage 196

Try 4, 6, 9, 11

Answers in Appendix J