IIIIIIIV Chemical Bonding Chapter 7 Section 1 Pages

Chemical Formulas zChemical formulas indicate the elements involved and how many of each type are in the molecule. C 8 H 18 Al 2 (SO 4 ) 3 subscripts

Types of Ions  Monatomic Ions – one element

Criss-Cross Method Used to write formulas of ionic compounds (salts) Step 1: List Charges of each ion Step 2: Criss-Cross the # of the Charge only! Step 3: Simplify (Never write a subscript of 1)

Criss-Cross means: # of the Charge of cation subscript of the anion. # of the Charge of anion subscript of the cation.

Types of Ions  Polyatomic – more than one element

Example: Calcium Phosphate Ca = PO 4 = Use parentheses for a polyatomic ion. Ca (PO 4 ) 2 3

Empirical Formula Lowest Whole Number Ratio of Elements CaSO 4 = 1 calcium ion for every 1 sulfate ion Na 2 SO 4 = 2 sodium ions for every 1 sulfate ion

*Stock System of Naming Compounds Roman numeral matching the charge is used. Ex: Cu +1, copper I Cu +2, copper II Cu +2 N0 3 - : Cu(N0 3 ) 2 copper II nitrate Cu + NO 3 - : CuNO 3 copper I nitrate

Naming Binary Ionic Compounds  Cation: Name the Metal (use Roman numerals for transition metals)  Anion: nonmetal Change the ending to –ide. Calcium Chloride Barium Oxide Potassium Sulfide Iron (III) Bromide Chromium (III) Oxide

Traditional Naming of Ionic Compounds Traditional naming of ionic compounds used the Latin names or some common names and a suffix corresponding to the charge as follows. Copper: Cuprum Cu +1 : cuprous Cu +2 : cupric The ous ending was used with the lower charged ion. The ic ending was used with the higher charged ion.

Tradition Names Ferrous Nitrate : Iron +2, nitrate: Fe(NO 3 ) 2 Plumbic Chloride: Lead +4, chlorine: PbCl 4 Latin Names: Ferrum – Iron, Cuprum – Copper, Stannum – Tin, Mercurum – Mercury Common Names: Any element with more than one possible charge: lead, mercury, tin, etc.

*Examples of Naming for Polyatomic Ions Calcium Sulfite Barium Phosphate Ammonium Sulfide Iron (III)Sulfite

Naming Molecular Compounds Same rules EXCEPT include prefixes NEVER start a compound name with mono- (drop the prefix) 1 = mono2 = di 3 = tri4 = tetra 5 = penta6 = hexa 7 = hepta8 = octa 9 = nona10 = deca

Naming Molecular Compounds NO 2 = nitrogen dioxide BF 3 = boron trifluoride P2O5P2O5 = diphosphorus pentoxide

*Molecular Formula Indicates how many atoms are in a single molecule of the compound. C 6 H 12 O 6 = glucose 6 carbon atoms 12 hydrogen atoms 6 oxygen atoms

Naming of Acids & Salts  Binary Acids: Contain only two elements.  Hydrogen & a nonmetal  Hydro- ____________ -ic acid. Ex: HCl = Hydrochloric Acid H 2 S = Hydrosulfuric Acid

Naming of Acids & Salts  Binary Salts: Contain only two elements.  A metal & a nonmetal  Name the metal & change the ending on the non-metal to –ide. Ex: NaCl = Sodium Chloride MgBr 2 = Magnesium Bromide

Naming of Acids & Salts  Ternary Acids: Prefix & Suffix  X could be any element other than (Sulfur, Phosphorus, Nitrogen or Carbon)  HXO = hypo-________-ous  HXO 2 = __________-ous  HXO 3 = __________-ic  HXO 4 = per-_________-ic

Naming of Acids & Salts  Example:  HClO = hypochlorous acid  HClO 2 = chlorous acid  HClO 3 = chloric acid  HClO 4 = perchloric

Naming of Acids & Salts  Ternary Salts: Prefix & Suffix  X could be any element other than (Sulfur, Phosphorus, Nitrogen or Carbon)  XO - = hypo-________-ite  XO 2 - = __________-ite  XO 3 - = __________-ate  XO 4 - = per-_________-ate

Naming of Acids & Salts  Example; Chlorine (X represents any metal)  XClO - = hypochlorite  XClO 2 - = chlorite  XClO 3 - = chlorate  XClO 4 - = perchlorate