More Nomenclature
What are covalent bonds?
 Result from a sharing of electrons between
participants
Covalent bonding
 Tight sharing of electron pairs between
2 or more elements
 Molecule – a neutral group of atoms
that are held together by covalent
bonds.
 Molecular compound – a chemical
compound whose simplest units are
molecules
Naming Binary Molecular
Compounds
 Less-electronegative atom
 Listed first
 Prefixes are required if more than one atom exists
 More-electronegative atom
 Listed second
 Prefix always required
 Ends in “ide”
 “o” or “a” of prefix is dropped with “oxide”
 Examples
 CO – carbon monoxide
 SCl4 – sulfur tetrachloride
 P2S5 – diphosphorus pentasulfide
 SPELLING COUNTS!
Prefixes
Number of Atoms
Prefix
1
2
3
4
5
6
7
8
9
10
monoditritetrapentahexaheptaoctanonadeca-
 Molecular formula indicates the actual
number and types of atoms in a molecule
 Empirical formula indicates only the
relative number of atoms of each type.
The subscripts are always the smallest
possible ratios.
ACIDS
Binary – only 2 elements
(usually H and halogen)
Oxyacid – hydrogen, oxygen
and 3rd element
Nomenclature of Acids
 No oxygen in the anion:




Prefix: hydroEnding: -ic acid
HCl – hydrochloric acid
HCN – hydrocyanic acid
 Oxyacids (oxygen in the anion):





No prefix
If the anion ends in –ate, the acid ends in –ic acid
If the anion ends in –ite, the acid ends in –ous acid
HC2H3O2 – acetic acid
HNO2 – nitrous acid
Simple organic compounds
 The study of compounds of carbon
is called organic chemistry.
 Compounds that contain carbon and
hydrogen – often with oxygen,
nitrogen and other elements are
organic compounds.
Alkanes
Compounds that contain only
carbon and hydrogen and
single bonds.
Named by number of carbons
Alkanes
 1- methane
 2 – ethane
 3 – propane
 4 – butane
 5 – pentane
 6 – hexane
 7 – heptane
 8 – octane
Alcohols – OH functional group
 If OH replaces one of the H’s in an
alkane it becomes an alcohol.
 Methanol
 Ethanol
 Propanol
 Butanol
Alcohol naming
Use a number prefix in front of an
alcohol to indicate which carbon
the OH is coming off of.
1-propanol
2-propanol