HONORS CHEMISTRYUnit C: Chemical Bonding, Formulas, Reactions & Equations
CHAPTER SEVEN: CHEMICAL FORMULAS & COMPOUNDS
NAMES & FORMULASuCHEMICAL FORMULAS indicate the
the elements present and the number of atoms of each element
uUses SYMBOLS and SUBSCRIPTSuSometimes uses PARENTHESES for
polyatomic ions
IONIC COMPOUND FORMULASuIONIC COMPOUNDS are
represented by FORMULA UNITS uReduced ratio of cation : anionuCATION 1st, ANION 2nd
uCHARGE COUNTS! (Must sum to zero)
ION CHARGESuIon charge is related to number valence
electronsuGroup 1: 1+ , Group 2: 2+ , Aluminum: 3+
uGroup 15: 3- , Group 16: 2- , Group 17: 1-
uTransition Metals are usually 2+, but can range from 1+ to 4+
uSPECIALS: Pb (lead) & Sn (tin) can be either 2+ or 4+
ION CHARGES
FORMULAS UNITSuCheck Charge! Sum to zero!uIf the charges are equal and
opposite then the ratio is 1:1uWhen charges are not equal
and opposite, SWAP & DROP!uUse parentheses for polyatomic
ions when multiple are included
NAMING IONIC COMPOUNDSuIonic compounds list the
cation first, anion seconduCation name is unchangeduAnion name is changed to
–ide ending by dropping the last syllable or two
uPolyatomic ions keep their name
ROMAN NUMERALSuROMAN NUMERALS are used
to indicate charge on transition metals, Pb, Sn
u I = 1uII = 2uIII = 3uIV = 4
MOLECULAR COMPOUNDSuMOLECULAR FORMULAS show
the the elements and actual number of atoms in a molecule
uThe formulas list the least electronegative element(s) first
uH2O, CO2, NO, PCl3
MOLECULAR COMPOUNDSuBINARY MOLECULAR
COMPOUND NAMES are simple and involve 2 elements
uGREEK PREFIXES are used to “describe” the number of atoms
uOnly the second element has an –ide ending change
MOLECULAR COMPOUNDS
ACIDSuACIDS are molecular
compoundsuCommon ACIDS have specific
namesuBINARY ACIDS contain
Hydrogen and and AnionuOXYACIDS contain Hydrogen,
Oxygen, and an additional (3rd) element
6 COMMON ACIDSuHCl – Hydrochloric AciduHNO3 – Nitric AciduH2SO4 – Sulfuric AciduH3PO4 – Phosphoric AciduCH3COOH (C2H4O2) – Acetic AciduH2CO3 – Carbonic Acid