Chapter 6:
Inorganic and Organic Compounds
6.5
Chem 1110
Figures: Basic Chemistry 3rd Ed., Timberlake and Timberlake
Ionic vs. Covalent Bonding
Ionic Bonding
Covalent Bonding
• Metal - nonmetal (NaCl)
• Electron transfer and
electrostatic interactions
• Formula Unit (from larger
arrays)
• Solids
• Two nonmetals (O2, H2O)
• Electron sharing in bonds
• Dissolve in water and
conduct electricity
• Discrete molecules
• All physical states (solid,
liquid and gas)
• If they dissolve in water,
they do not conduct
electricity
The Covalent Bond
Covalent Bonding: a chemical bond that results from
two nuclei attracting the same shared electron pair
Forming a H2 Molecule
• A covalent bond forms as two H atoms
move close together to share electrons
Diatomic Elements
Several elements share electrons to form
diatomic, covalent molecules:
Octet Rule
Covalent compounds also obey the Octet Rule:
• Each atom in the bond is seeking a noble gas
configuration
• Electrons are shared to achieve the octet
• For Example:
Br → needs 1 electron to achieve an octet
Lewis Dot Structures
• We can use Lewis Dot structures to help
us form Covalent Bonds:
H with Cl
H with O
P with Br
Electron-Dot Formulas
Electron-dot formulas:
• the order of bonded atoms in a
covalent compound
• the bonding pairs of electrons
between atoms
• the unshared (lone) valence
electrons
• a central atom with an octet
Covalent Compounds
Bonding and Lone Pair Electrons
• Bonding pair of electrons are shared to
create the covalent bond
• Non-bonding pair or lone pair make up
the octet
Bonding and Lone Pair Electrons
• Bonding pair of electrons are shared to create the
covalent bond
• Non-bonding pair or lone pair make up the octet
Cl2
HBr
H2S
Naming Covalent Compounds
1) Most metallic atom comes first then the more
negative + “-ide”
2) Name includes the total
number of each atom:
For Example:
NO
NO2
N2O
Table 6.10 (p. 178)
Naming Covalent Compounds
For Example:
SiBr4
P4O10
Naming Covalent Compounds
• Many covalent compounds have common
names that you are most likely familiar with:
NH3
H2O
H2S
CH4
Formulas and Names of Some
Covalent Compounds
Learning Check
Select the correct name for each compound:
A.
SiCl4
1) silicon chloride
2) tetrasilicon chloride
3) silicon tetrachloride
B.
P2O5
1) phosphorus oxide
2) phosphorus pentoxide
3) diphosphorus pentoxide
C.
Cl2O7
1) dichlorine heptoxide
2) dichlorine oxide
3) chlorine heptoxide
Learning Check
Write the name of each covalent compound:
CO
_____________________
CO2
_____________________
PCl3
_____________________
CCl4
_____________________
N2O
_____________________