Post on 14-Dec-2015
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
• Dissolve in water and conduct electricity
• Two nonmetals (O2, H2O)
• Electron sharing in bonds
• Discrete molecules
• All physical states (solid, liquid and gas)
• If they dissolve in water, they do not conduct electricity
The Covalent BondCovalent Bonding: a chemical bond that results from two nuclei attracting the same shared electron pair
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
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 Compounds1) Most metallic atom comes first then the more
negative + “-ide”
For Example:
NO
NO2
N2O
2) Name includes the total number of each atom:
Table 6.10 (p. 178)
Naming Covalent Compounds
• Many covalent compounds have common names that you are most likely familiar with:
NH3
H2O
H2S
CH4
Select the correct name for each compound:
A. SiCl4 1) silicon chloride2) tetrasilicon chloride3) silicon tetrachloride
B. P2O5 1) phosphorus oxide2) phosphorus pentoxide3) diphosphorus pentoxide
C. Cl2O7 1) dichlorine heptoxide2) dichlorine oxide3) chlorine heptoxide
Learning Check