Type II Binary Ionic Compounds

1
Type II Binary Ionic Compounds

• Type II binary ionic compounds contain a metal
  that can form more than one type of cation.
• (aka Transition Metals)

2
Some metals are predictable

• Group 1 alkali metals always form 1
  cations
• Group 2 alkaline earth metals always form 2
  cations
• Aluminum always form 3 cations

3
Transition Metals can have more than one cation

• Roman numerals are used to determine which cation
  is present.
• We can determine the charge on the cation by
  looking at the anion whose charge doesnt change.

4
FeCl2

• Cl always has a 1- charge
• So, if the compound has two Cl present the total
  negative charge is 2-
• But, the compound must be neutral so the Fe must
  have a charge of 2 to equal out the Cl
• It is written as Fe(II)Cl2

5
FeCl3

• Here we have a 3- charge from the 3 Cl
• So, the Fe must have a charge of 3
• Fe(III)Cl3

6
The Roman Numeral tells the charge on the ion,
not the number of ions present
7
Common Type II Cations
Ion Systematic Name Older Name Ion Systematic Name Older Name
Fe3 Iron (III) Ferric Sn4 Tin (IV) Stannic
Fe2 Iron (II) Ferrous Sn2 Tin (II) Stannous
Cu2 Copper (II) Cupric Pb4 Lead (IV) Plumbic
Cu Copper (I) Cuprous Pb2 Lead (II) Plumbous
Co3 Cobalt (III) Cobaltic Hg2 Mercury (II) Mercuric
Co2 Cobalt (II) Cobaltous Hg22 Mercury (I) Mercurous
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Practice

• CuCl
• Cu (I) because Cl is 1-
• Fe2O3
• Fe(III) because O is 2-
• PbCl4
• Pb(IV) because Cl is 1-
• MnO2
• Mn(IV) because O is 2-

9
What is the formula for each of the following?

• Sn(IV) and Cl
• SnCl4
• Pb(II) and I
• PbI2
• Co(III) and O
• Co2O3

10
And

• Cu(II) and SO4
• CuSO4
• Cu(I) and SO4
• Cu2SO4
• Fe(III) and NO3
• Fe(NO3)3

11
Review of Type II Binary Ionic Compounds

• The compound must be neutral
• The anions will always be negative and they will
  always be the same
• The cations will change they are transition
  metals
• We can determine the charge on the cation by
  finding the charge on the anion first

12
Lets take ZnCl2

• What is the charge on the Zn?
• Since Cl is always 1- there is a 2- charge on the
  compound
• So, that means Zn must be 2

13
SnO2

• In this case O is always 2-
• So, the overall negative charge is 4-
• Therefore, Sn will have a charge of 4

14
Fe2(SO4)3

• Since SO4 is always 2- we have a total of 6-
  charge on the anion
• Therefore, the Iron must have 6 charge all
  together
• Since there are 2 Fe the charge on each must be 3

15
Ag2C8H4O2

• The C8H4O2 always has a charge of 2-
• Therefore the Ag must be 1 each so that we have
  a total of 2