“How Do We Name Compounds?” Nomenclature “How Do We Name Compounds?”

Systematic Naming Compounds are made up of two or more elements Name should tell us how many and what type of atoms Too many compounds to remember all the names

Metals

Metals Qualities of Metals Luster – shiny Ductile – think making it into wires Malleable – hammer it into sheets Good conductors of heat and electricity

Transition Metals

Non-metals

Metalloids or Semimetals

Cation Anion Positive ion Formed by losing electrons Metals form cations Anion Negative ion Has gained electrons Non metals form anions

Ionic Compounds Made of cations and anions Metals and nonmetals Electrons lost by the cation are gained by the anion

Ionic Compounds Cl Na + Na + Cl Sodium is cation Chlorine is anion 1- 1+ Na + Na + Cl Chlorine is anion

Charges on Ions

Naming Ions Metal ion is written first in both name and formula It is named directly from element which formed the ion. Will nearly always be the positive ion or “cation” Transition metals can have more than one type of charge Indicate the charge with roman numerals in parenthesis. Iron(II) or Iron(III) Exceptions: Silver always +1 Cadmium and Zinc always +2

Name these Na 1+ Ca 2+ Al 3+ Fe 3+ Fe 2+ Pb 2+ Li 1+ Sodium Calcium Aluminum Iron (III) Iron (II) Lead (II) Lithium

Write Formulas for these Potassium ion Magnesium ion Copper (II) ion Chromium (VI) ion Barium ion Mercury (II) ion K1+ Mg2+ Cu2+ Cr4+ Ba2+ Hg2+

Naming Anions Anions are always the same. Change the element ending to -- ide F1- Fluorine to Fluoride

Name These Chloride Cl1- Nitride N3- Bromide Br 1- Oxide O2- Iodide Strontium Cl1- N3- Br 1- O2- I1- Sr2+

Write These Sulfide ion Iodide ion Phosphide ion Strontium ion S2- I1- Sr2+

Polyatomic Ions Tightly bound groups of atoms acting as a single ion. Names given in table in book. (pg 123) Most are anions that contain oxygen. Names end in –ate (one more O), or –ite (one less O). SO32- = sulfite; SO42- = sulfate Exceptions: Ammonium cation NH4+, Cyanide CN-, and hydroxide OH-

Naming Binary Ionic Compounds 2 elements involved Ionic – metal (cation) and a non-metal (anion) Naming is easy with representative elements in A groups NaCl = Na+ Cl- = sodium chloride MgBr2 = Mg2+Br- = magnesium bromide

Naming Binary Ionic Compounds The problem comes with the transition metals. Need to figure out their charges All ionic compounds will have a neutral charge Same number of + and – charges Use the anion to determine the charge on the positive ion.

Naming Binary Ionic Compounds Try naming these KCl Na3N CrN ScP PbO PbO2 Na2Se Potassium chloride Sodium nitride Chromium (III) nitride Scandium (III) phosphide Lead (II) oxide Lead (IV) oxide Sodium selenide

Ternary Ionic Compounds Will have polyatomic ions At least 3 elements Use blue sheet Name these ions NaNO3 CaSO4 CuSO3 (NH4)2O LiCN Fe(OH)3 (NH4)2CO3 NiPO4 Sodium nitrate Calcium sulfate Copper (II) sulfite Ammonium oxide Lithium cyanide Iron (III) hydroxide Ammonium carbonate Nickel (III) phosphate

Writing Formulas Net charge must add to zero. Get charges of cation/anion Balance the charges Put polyatomics in parenthesis

Writing Formulas Write formula for calcium chloride Calcium is Ca2+ Chloride is Cl1- Ca+2Cl-1 would have a +1 charge Need another Cl1- Ca+2Cl2-1 = CaCl2

CaCl2 Ca2+ Cl1- Fe 3+ S2- Fe 2 S3 Writing Formulas Fe2S3 Crisscross method Calcium chloride CaCl2 Ca2+ Cl1- No need to write the one Iron (III) sulfide Fe 3+ S2- Fe 2 S3 Fe2S3

Write Formulas for These Lithium sulfide Tin (II) oxide Tin (IV) oxide Magnesium fluoride Copper (II) sulfate Iron (III) phosphide Iron (III) sulfide Ammonium chloride Ammonium sulfide Li2S SnO SnO2 MgF2 CuSO4 FeP Fe2S3 (NH4)Cl (NH4)2S

Things to Look For If cations have ( ), the roman numeral is their charge. If anions end in –ide they probably are off the periodic table (monoatomic) If anion ends in –ate or –ite it is a polyatomic ion