1. Nomenclature (Naming Compounds) Writing Formulas
Chapter 2 Part 2
Nomenclature
(Naming Compounds)
Writing Formulas

2. Systematic Naming
There are too many compounds to remember the names of them all.
Compound is made of two or more elements.
Name should tell us how many and what type of atoms.
Rules were established

3. Representative elements1 20 15 2 17 13 14 16
The Main Group elements

4. Transition metals
The transition, or groups 3-12 elements

5. Types of Particles
There are three types of particles all matter is made off:
IONS (ionic compounds, metals)
ATOMS (Noble gases)
MOLECULES (molecular compounds)

6. Atoms and Ions Atoms are electrically neutral.
Same number of protons and electrons.
Ions are atoms, or groups of atoms, with a charge.
Different numbers of protons and electrons.
Only electrons can move.
Negative ions formed by gaining electron
Positive ions formed by losing electrons.

7. F-1 O-2 Anion A negative ion. Has gained electrons.
Only non metals can gain electrons.
Charge is written as a superscript on the right.
F-1
Has gained one electron
O-2
Has gained two electrons

8. K+1 Ca+2 Cations Positive ions. Formed by losing electrons.
More protons than electrons.
Metals form cations.
K+1
Has lost one electron
Ca+2
Has lost two electrons

9. Types of Chemical Bonds
IONIC:
positive and negative ions attract each other. (Electrostatic attraction)
COVALENT:
two atoms share one or more (up to three) pairs of electrons
METALLIC:
positive ions are surrounded by freely moving electrons (metals)

10. Compounds Follow the Law of Definite Proportion.
Have a constant composition.
Two types: ionic and molecular.

11. Two Types of Compounds Molecular compounds Made of molecules.
Made by joining nonmetal atoms together into molecules.

12. Two Types of Compounds Ionic Compounds
Made of cations and anions.
Metals and nonmetals or polyatomic ions.
The electrons lost by the cation are gained by the anion.
The cation and anions surround each other.
Smallest piece is a FORMULA UNIT.

13. Two Types of Compounds Ionic Molecular Smallest piece Formula Unit
Molecule
Types of elements
Metal and Nonmetal, polyatomic ions
Nonmetals
Solid, liquid or gas
State
solid
Melting Point
Low <300ºC, depends on molecular mass
High >300ºC

14. Chemical Formulas
Shows the kind (identity) and number of atoms in the smallest piece of a substance. Shorthand notation.
Molecular formula- number and kinds of atoms in a molecule. Indicated by a SUBSCRIPT
CO2
C6H12O6

15. Types of Formulas (1) Molecular formula: Formula unit:
indicates the composition of a molecular compound.
Formula unit:
depicts the composition of an ionic compound. Shows the ratio between the ions in the formula.

16. Types of Formulas (2) Structural formula:
depicts the structure of a molecule, or an ion. Shows the bonding pattern within the unit.
Condensed structural formulas:
hybrid between molecular and structural formulas. Highlights the presence of reactive or special groups.

17. Types of Formulas (3) EMPIRICAL FORMULA: Ionic compounds :
indicates the simplest whole-number ratios in which atoms of the elements are present in the compound
Ionic compounds :
usually represented by empirical formula (NaCl). Exception: Hg2Cl2

18. Writing names and Formulas
Molecular Compounds
Writing names and Formulas

19. Molecular Compounds
hemoglobin
water

20. Molecules
Small group of atoms held together by covalent bonds. Made up from non-metallic elements only!!!!
Neutral particles.
#protons = # electrons
Examples: CH4, NO2, CO, CO2, C6H12O6, C2H6

21. Nomenclature of Molecules
Molecular compounds name tells you the number of atoms.
Uses prefixes to tell the number of atoms

22. Prefixes 1 mono- 2 di- 3 tri- 4 tetra- 5 penta- 6 hexa- 7 hepta-
8 octa-

23. Prefixes
9 nona-
10 deca-
To write the name write two words

24. Prefixes 1- Prefix name 2- Prefix name + -ide 9 nona- 10 deca-
To write the name write two words
1- Prefix
name
2- Prefix
name
+ -ide

25. Prefixes Prefix name Prefix name -ide 9 nona- 10 deca-
To write the name write two words
One exception is we don’t write mono- if there is only one of the first element.
Prefix
name
Prefix
name
-ide

26. Prefixes Prefix name Prefix name -ide 9 nona- 10 deca-
To write the name write two words
One exception is we don’t write mono- if there is only one of the first element.
No double vowels when writing names (oa oo)
Prefix
name
Prefix
name
-ide

27. Write formulas for these
diphosphorus trioxide
tetraiodide nonoxide
sulfur hexachloride
dinitrogen trioxide
carbon tetrachloride
diphosphorus trisulfide
magnesium nitride

28. Ionic Compounds Represented by formula unit
The smallest whole number ratio of atoms in an ionic compound.
Ions surround each other so you can’t say which is hooked to which.

29. Ionic compounds

30. Ionic Compounds

31. Charges on Ions
For most of the Representative Elements (Groups 1, 2, elements), the Periodic Table can tell what kind of ion they will form from their location.
Elements in the same group have similar properties.
Including the charge when they are ions.

32. Group 14: does not form ions+1 +2 +3 -3 -2 -1

33. What about the others? We have to figure those out some other way.
Check the periodic table
Examples:

34. Naming ions We will use the systematic way.
Cation- if the charge is always the same (Group 1) just write the name of the metal.
Transition metals can have more than one type of charge.
Indicate the charge with Roman numerals in parenthesis.

35. Name these
Na+1
Ca+2
Al+3
Fe+3
Fe+2
Pb+2
Li+1

36. Write Formulas for these
Potassium ion
Magnesium ion
Copper (II) ion
Chromium (VI) ion
Barium ion
Mercury (II) ion

37. Naming Anions Anions are always the same.
Change the element ending to – ide
F-1 Fluorine change to fluoride

38. Name these
Cl-1
N-3
Br-1
O-2
Ga+3

39. Write these
Sulfide ion
iodide ion
phosphide ion
Strontium ion

40. Polyatomic ions Groups of atoms that stay together and have a charge.
You must memorize these.
Acetate C2H3O2-1
Nitrate NO3-1
Nitrite NO2-1
Hydroxide OH-1
Permanganate MnO4-1
Cyanide CN-1

41. Polyatomic ions Sulfate SO4-2 Sulfite SO3-2 Carbonate CO3-2
Chromate CrO4-2
Dichromate Cr2O7-2
Phosphate PO4-3
Phosphite PO3-3
Ammonium NH4+1

42. Ions in Ionic Compounds

43. Naming Binary Ionic Compounds
Binary Compounds - 2 elements.
Ionic - a cation and an anion.
To write the names just name the two ions.
Easy with Representative elements.
Group 1
NaCl = Na+ Cl- = sodium chloride
MgBr2 = Mg+2 Br- = magnesium bromide

44. Naming Binary Ionic Compounds
The problem comes with the transition metals.
Need to figure out their charges.
The compound must be neutral.
same number of + and – charges.
Use the anion to determine the charge on the positive ion.

45. Naming Binary Ionic Compounds
Write the name of CuO
Need the charge of Cu
O is -2
copper must be +2
Copper (II) chloride
Name CoCl3
Cl is -1 and there are three of them = -3
Co must be +3 Cobalt (III) chloride

46. Naming Binary Ionic Compounds
Write the name of Cu2S.
Since S is -2, the Cu2 must be +2, so each one is +1.
copper (I) sulfide
Fe2O3
Each O is x -2 = -6
3 Fe must = +6, so each is +2.
iron (III) oxide

47. Naming Binary Ionic Compounds
Write the names of the following
KCl
Na3N
CrN
Sc3P2
PbO
PbO2
Na2Se

48. Ternary Ionic Compounds
Will have polyatomic ions
At least three elements
name the ions
NaNO3
CaSO4
CuSO3
(NH4)2O

49. Ternary Ionic Compounds
LiCN
Fe(OH)3
(NH4)2CO3
NiPO4

50. Writing Formulas The charges have to add up to zero.
Get charges on pieces.
Cations from name of table.
Anions from table or polyatomic.
Balance the charges by adding subscripts.
Put polyatomics in parenthesis.

51. Writing Formulas Write the formula for calcium chloride.
Calcium is Ca+2
Chloride is Cl-1
Ca+2 Cl-1 would have a +1 charge.
Need another Cl-1
Ca+2 Cl2-1

52. Write the formulas for these
Lithium sulfide
tin (II) oxide
tin (IV) oxide
Magnesium fluoride
Copper (II) sulfate
Iron (III) phosphide
gallium nitrate
Iron (III) sulfide

53. Write the formulas for these
Ammonium chloride
ammonium sulfide
barium nitrate

54. Things to look for If cations have (), the number is their charge.
If anions end in -ide they are probably off the periodic table (Monoatomic)
If anion ends in -ate or -ite it is polyatomic

55. Writing names and Formulas
Acids
Writing names and Formulas

56. Acids Compounds that give off hydrogen ions when dissolved in water.
Must have H in them.
will always be some H next to an anion.
The anion determines the name.

57. Naming acids
If the anion attached to hydrogen is ends in -ide, put the prefix hydro- and change -ide to -ic acid
HCl - hydrogen ion and chloride ion
hydrochloric acid
H2S hydrogen ion and sulfide ion
hydrosulfuric acid

58. Naming Acids If the anion has oxygen in it it ends in -ate of -ite
change the suffix -ate to -ic acid
HNO3 Hydrogen and nitrate ions
Nitric acid
change the suffix -ite to -ous acid
HNO2 Hydrogen and nitrite ions
Nitrous acid

59. Name These
N2O5
N2O4
Cl2O3
CI4 CO
CuCl2

60. Name these HF
H3P
H2SO4
H2SO3
HCN
H2CrO4

61. Write formulas for these
hydroiodic acid
acetic acid
carbonic acid
phosphorous acid
hydrobromic acid

62. Writing Formulas Hydrogen will always be first
name will tell you the anion
make the charges cancel out.
Starts with hydro- no oxygen, -ide
no hydro, -ate comes from -ic, -ite comes from -ous