1. Chemical Nomenclature: Formula Writing & Naming Compounds

2. Chemical Formula
The representation of a substance using symbols (letters) and subscripts (numbers)
H2O
The subscripts tell you how many atoms a compound is composed of. Water is made of 2 atoms of Hydrogen and atom of oxygen

3. Writing Formulas for Binary Molecules aka Binary Covalent Compounds.
made of 2 different elements
Molecules are Covalently bonded together
Both elements are non-metals
To the right of the “staircase” AND Hydrogen

4. Ex. Phosphorus pentoxide PO5
Write the symbols for the elements in order
ide refers to an element except peroxide & hydroxide
Subscripts are written from prefixes and follow the symbol
Mono = one Di = two Tri = three
Tetra = four Penta = Hexa = 6

5. Practice Carbon dioxide Dihydrogen monoxide Sulfur hexafluoride
Mono never
STARTS a name!
Practice
Carbon dioxide
CO2
Dihydrogen monoxide
H2O
Sulfur hexafluoride
SF6
Phosphorous pentachloride
PCl5

6. Formula Writing for Ionic Compounds
All ionic formulas are made of 2 parts
A / B
A is positive B is negative
A can be:
Metal or
Polyatomic ion
B can be:
Non-Metal or
Polyatomic ion

7. Ionic Names with Roman Numerals
Copper II Chloride Copper II Chlorate
Write the symbols
( -ate is a polyatomic ion)
The positive oxidation state for the metal is given to you as a Roman Numeral
You know the charge on the anion. It’s based on the number of valence e-

8. CuCl2 Cu(ClO3)2 Make your charges cancel out
Write formula & reduce if you can
“1” doesn’t need to be written
CuCl2
Cu(ClO3)2

9. Practice
Lead II oxide
PbO
Lead IV oxide
PbO2

10. Ionic Names without Roman Numerals
Potassium Nitride Potassium Nitrate
Write down the symbols
If polyatomic ion look it up and write it in parenthesis. Don’t change it!
Assign oxidation states / charges
Part A will be positive: you should know it!
Part B will be negative and you should know them  or it’s a PAI (look it up)

11. K3N KNO3 “Crisscross” 4. Write formula - REDUCE!
“1” doesn’t need to be written
K3N
KNO3

12. Practice
Calcium Phosphate Ca3(PO4)2
Magnesium Hydroxide Mg(OH)2

13. Formula Writing for 2 polyatomic ions
Ammonium Phosphate
Write separate formulas in parenthesis
NEVER change what’s inside!!!!!!!!!!
Assign charges
Make the charges cancel out with subscripts & write your final answer…….. (NH4)3PO4

14. Practice
Ammonium Nitrate NH4NO3
Ammonium Hydroxide NH4OH

15. Naming……..

16. Naming Binary Molecules . . . both elements are non-metals
Count the number of atoms as a prefix
mono = one
di = two
tri = three
tetra = four . . .
2. Write the prefix before the names of the elements
Mono never STARTS a name

17. Write the name of the second element
end the name with -ide
hydrogen hydride
oxygen oxide
nitrogen nitride
sulfur sulfide
fluorine fluoride
chlorine chloride
bromine bromide
Practice
CO2 carbon dioxide
N2O dinitrogen monoxide
SCl5 sulfur pentachloride
H2O dihydrogen monoxide
CCl4 carbon tetrachloride

18. Naming when the formula starts with a metal
MgCl FeCl2
Name the first element
Check if this element is a transition metal or Tin or Lead
no just name the second part
yes assign the negative oxidation state first then determine the positive
write it as a Roman Numeral

19. Practice CuSO4 Copper II sulfate Ba(OH)2 Barium hydroxide
Remember: You only need a roman numeral if you have a transition metal, or Sn or Pb….but not Zn or Ag
Practice
CuSO4 Copper II sulfate
Ba(OH)2 Barium hydroxide
Al2S3 aluminum sulfide
CuCl copper I chloride
CuCO3 copper II carbonate

20. Naming polyatomic ion - element compounds
NH4Cl
No prefixes
No roman numerals just name it!
Practice
NH4F ammonium fluoride
(NH4)2S ammonium sulfide

21. Naming compounds with 2 polyatomic ions
Just name them!
Practice
(NH4)2SO ammonium sulfate
(NH4)2CrO ammonium chromate
(NH4)3PO ammonium phosphate

22. The End