1. Chapter 2 The Material World
Molecules
Chapter 2
The Material World

2. Forming Ionic Compounds (with transition metals)

3. What are transition metals?
Transition metals are the metals located in the middle of the periodic table (in the “B” section)

4. What are transition metals?
Transition metals are the metals located in the middle of the periodic table (in the “B” section)
These metals have various oxidation states
In other words: these are elements that can take on different charges
Fe2+
Fe3+

5. Examples These are the possible oxidation states
(charges) that the element can take on

6. These are the most common oxidation states
(charges) that the element can take on

7. Naming Ionic Compounds with Transition Metals
RULE: Transition Metal Name (Roman numeral of oxidation state) + Non-Metal Name (modified ide ending)
Still ignoring the subscripts!
Examples:
Cu2O  Copper (I) Oxide
CrCl3  Chromium (III) chloride
MnO  Manganese (II) oxide

8. How do we know which oxidation state to use?
Backwards Crossover Method!

9. Backwards Crossover Method
Cu O 2 1
Means that Copper has a charge of +1 (because it’s a metal and donates the electron)
Copper
(I)
oxide

10. Backwards Crossover Method
Cr Cl 1 3
Means that Chromium has a charge of +3 (because it’s a metal and donates the electrons)
Chromium
(III)
chloride

11. Backwards Crossover Method2 2
Mn O
But wait! We KNOW oxygen has a charge of -2 1 1
That means manganese must have a charge of +2
Manganese
(II)
oxide

12. Forming Ionic Compounds (with polyatomic ions)

13. What are polyatomic ions?
Polyatomic ions are a group of atoms that, as a group, have a charge
Polyatomic = multiple atoms
Ions = charged particles
This means that these groups can form ionic bonds with other ions (metals and non-metals)!

14. Ion (chemical formula)
Name
NH4 +
ammonium
CO3 -2
carbonate
NO2 -
Nitrite
HCO3 -
hydrogen carbonate
(often also called bicarbonate)
NO3 -
nitrate
ClO -
hypochlorite
SO3 -2
sulfite
ClO2-
chlorite
SO4 -2
sulfate
ClO3 -
chlorate
HSO4 -
hydrogen sulphate
(bisulfate is a widely used common name)
ClO4 -
perchlorate
OH -
hydroxide
C2H3O2 -
acetate
CN -
cyanide
MnO4 -
permanganate
PO4 -3
phosphate
Cr2O7 -2
dichromate
HPO4 -2
hydrogen phosphate
CrO4 -2
chromate
H2PO4 -
dihydrogen phosphate
O2 -2
peroxide

15. Naming Ionic Compounds with Polyatomic Ions
RULE: Same as for binary ionic compounds but use the name of the polyatomic ion - Never change the ending of the polyatomic ion’s name
Examples:
AlPO4  Aluminum phosphate
Ba(CN)2  Barium cyanide
NH4NO3  Ammonium nitrate
Still ignoring the subscripts!

16. Naming Ionic Compounds – Polyatomics + Transition metals!
FeSO4
Iron (II) sulfate
Cu(ClO3)2
Copper (II) chlorate