1. Chapter 3 Chemical Bonding
(3.4) Chemical Formulas - Ionic

2. Writing Formulas–Binary Compounds
contain H, metal or metalloid with only 1 oxidation number (or valence) (see periodic table for values)
name the first element and change the ending (suffix) of second element to “ide”
Use zero sum rule to write formula
Try Table 1

3. Chemical Formulas - Practice Table 1
Br1-
N3-
K1+
Mg2+
Al3+
K2S
KBr
K3N
potassium sulfide
potassium bromide
potassium nitride
Mg3N2
magnesium nitride
MgS
magnesium sulfide
MgBr2
magnesium bromide
Al2S3
aluminum sulfide
AlBr3
aluminum bromide
AlN
aluminum nitride

4. Tertiary Compounds
contain polyatomic ions (see periodic table given in class)
name the first element and then the polyatomic ion
Use zero sum rule to write formula
Try Table 2

5. Chemical Formulas - Practice Table 2
OH1-
CO32-
PO43-
Mg2+
Li1+
NH41+
hydroxide
carbonate
phosphate
Mg(OH)2
MgCO3
magnesium carbonate
Mg3(PO4) 2
magnesium phosphate
magnesium hydroxide
LiOH
lithium hydroxide
Li2CO3
lithium carbonate
Li3PO4
lithium phosphate
(NH4)2CO3
ammonium carbonate
NH4OH
ammonium hydroxide
(NH4)3PO4
ammonium phosphate
ammonium

6. Writing Formulas – Multivalent Ions
When the first element has more than 1 oxidation number (or valence)
IUPAC System (Stock System)
Use Roman numeral to indicate valence of more electronegative element
Ex:
Cu1+ copper (I)
Cu2+ copper (II)
Note: Hg2+ mercury (II)
Hg22+ (Hg1+)mercury (I)

7. Writing Formulas – Multivalent Ions
Old system(Classical System)(ic/ous)
Use suffix “ic” for highest valence and “ous” for lowest
Use classical name of element (see table provided on next slide)
Next….try Table 3

8. Table: Multivalent Ion Names
Formula
IUPAC Name
Classical Name
Cu1+
copper (I)
Cu2+
copper (II)
Fe2+
iron (II)
Fe3+
iron (III)
Hg22+ (Hg1+)
mercury (I)
Hg2+
mercury (II)
Pb2+
lead (II)
Pb4+
lead (IV)
Sn2+
tin (II)
Sn4+
tin (IV)
Cr2+
chromium (II)
Cr3+
chromium (III)
Mn2+
manganese (II)
Mn3+
manganese (III)
Mn4+
manganese (IV)
Co2+
cobalt(II)
Co3+
cobalt(III)
Au1+
gold (I)
Au3+
gold (III)
Table: Multivalent Ion Names

9. Table: Multivalent Ion Names
Formula
IUPAC Name
Classical Name
Cu1+
copper (I)
cuprous
Cu2+
copper (II)
cupric
Fe2+
iron (II)
ferrous
Fe3+
iron (III)
ferric
Hg22+ (Hg1+)
mercury (I)
mercurous
Hg2+
mercury (II)
mercuric
Pb2+
lead (II)
plumbous
Pb4+
lead (IV)
plumbic
Sn2+
tin (II)
stannous
Sn4+
tin (IV)
stannic
Cr2+
chromium (II)
chromous
Cr3+
chromium (III)
chromic
Mn2+
manganese (II)
Mn3+
manganese (III)
Mn4+
manganese (IV)
Co2+
cobalt(II)
cobaltous
Co3+
cobalt(III)
cobaltic
Au1+
gold (I)
aurous
Au3+
gold (III)
auric
Table: Multivalent Ion Names

10. Chemical Formulas - Practice Table 3
IUPAC
Old System
FeCl2
FeCl3
copper (I) fluoride
nickel (II) sulfide
ferric oxide
mercuric oxide
iron (II) chloride
ferrous chloride
iron (III) chloride
ferric chloride
CuF
cuprous fluoride
NiS
nickelous sulfide
Fe2O3
iron (III) oxide
HgO
mercury (II) oxide

11. Writing Formulas – Polyatomic Ions
Some polyatomic ions contain the same types of atoms but different numbers of each type.
(see periodic table given in class)

12. Writing Formulas – Polyatomic Ions
For the related ions, only the “ate” ions need to be memorized, others may be found following this pattern:
Step method:

13. Writing Formulas – Polyatomic Ions
For the related ions, only the “ate” ions need to be memorized, others may be found following this pattern:
Step method:
As you move up one step…the # of oxygen atoms increases by 1
Charge on ion stays the same
hypo
ite
ate
per

14. Oxy-Acid Radicals Try the oxy-acid radicals handout provided
Note: Elements in the same group on the periodic table form the same polyatomic ion.

15. Homework Text: Read p95-105 Worksheet 3.4 –Ionic Compounds
typo: ans Q#14 O2m O22-
Worksheet - “Oxy-Acid Radicals”
Reminder: Lab Fee?