1. Nomenclature
Chapter 4

2. Nomenclature = Naming
Common names were created before there was a system in place
More than 4 million chemical compounds, memorizing names would be impossible
A system makes it much easier

3. Binary Compounds Compounds composed of 2 elements 2 types
Metal and Nonmetal
Two Nonmetals

4. 4.1 Naming Compounds That Contain a Metal and a Nonmetal
Remember: When metals and nonmetals combine the compound contains ions
Resulting substance is a binary ionic compound
Contain cation and anion in that order
To name them simply name ions
Cation is element name
Anion is root of element name with –ide at end
NaCl is sodium chloride

5. Certain metal ions form only one cation
Na is always Na+
Cs is always Cs+
Ca is always Ca2+
We will call these Type I cations and they form Type I binary compounds
Other metal ions can form more than one cation
Cr can form Cr2+ or Cr3+
Lower oxidation number will end in –ous
Higher oxidation number will end in -ic
We will call these Type II cations and they form Type II binary compounds

6. Type I Binary Ionic Compounds
Cation always named first, anion second
When a single element is the cation we simply use its name
When a single element is the anion take the root and add –ide
Examples
NaI is sodium iodide
CaO is calcium oxide
What would KI be? Potassium iodide
What would CsBr be? Cesium bromide
Do Practice problems on page 87

7. Type II Binary Ionic Compounds
Need to specify which cation is used
Is it Cr2+ or Cr3+?
We will use Roman Numerals in name
So if it is FeCl2 which Iron is it? Fe2+ (the ferrous ion) or Fe3+ (the ferric ion)?
we know Chlorine has a 1- oxidation number so 2 (1-) = 2-, what must Fe be to cancel this out?
Fe must be 2+ so it is Fe2+
So name would be Iron II chloride
Table 4.2 page 90

8. 4.2 Binary Compounds That Contain Only Nonmetals (Type III)
Write first element
Write second element
Add prefix to 1st element (but not mono-)
Add prefix to 2nd element
Why do we do this?
NO, N2O5, and NO2 would all be nitrogen oxide under the normal rules
Instead they are Nitrogen monoxide, Dinitrogen pentoxide, and Nitrogen dioxide
one –mono
two - di
three - tri
four - tetra
five - penta
six - hexa
seven - hepta
eight - octa
nine - nona
ten - deca

9. 4.3 Review Type I Type II Type III metal and nonmetal
Metal cation has only 1 oxidation number
Type II
Metal and nonmetal
Metal cation has more than 1 oxidation number
Tell which ox. # it is with roman numerals
Type III
Nonmetal and nonmetal
Use prefixes to name

10. Naming Binary Compounds

11. 4.4 naming Compounds That Contain Polyatomic Ions
FIRST: Copy Table 4.4 on page 100 into notes
Polyatomic ion – a charged group of atoms bound together
Oxyanion – oxygen and another element
Smallest – hypo-
Lower - -ite (If only 2, smallest)
Higher - - ate (If only 2, largest)
Largest – hyper

12. When naming compounds with polyatomic ions follow same rules but anion (second part of formula) is a polyatomic ion just name it

13. 4.5 Naming Acids Acid – produces H+ ions (protons) in water
Tastes sour (not a good test)
It is like a molecule with a H+ attached to an anion
If no oxygen
Hydro- in front, -ic at end
HCl is Hydrochloric acid
If oxygen
Root of central element of anion or anion name with –ic or –ous
Anion ends in –ate then replace with –ic
Anion ends with –ite then replace with -ous

14. 4.6 Writing Formulas From Names
You know how to do this