Topic :Intro to Organic Chemistry
– hydrocarbons
Do Now: read p.1 – amazing
carbon
Organic chemistry = carbon
compounds (except oxides,
carbides (C + element that is less
electronegative), & carbonates)
Bonding Capacity
•
•
•
•
•
H can form only 1 bond
The halogens (F, Cl, Br, I) form only 1 bond
O and S like to form 2 bonds
N and P form 3 bonds
C form 4 bonds
Why so many C compounds?
• Carbon atoms can bond with other carbon
atoms in chains, rings, and networks
• Bonds are covalent
Lewis Diagram of C
•
•C•
•
Carbon has 4 unpaired electrons so
it can form 4 covalent bonds
Chemical Formulas
• show kind & # of atoms
CH3OH
CH2Cl2
CH4
CH3Cl
Structural Formulas
• show kind & # of atoms
• show bonds
• 2-D picture
Structural Formulas
• single line (–) represents one pair of
electrons (a single bond)
• double line (=)represents two pairs of
electrons (a double bond)
●
triple line ()represents three pairs of
electrons (a triple bond)
Condensed Structural Formula
• shows kind & # of atoms
• shows some structural information, but not all
details
structural formula:
Condensed structural formula:
CH3CH2CH3
We will be looking at 3 Homologous
Series of Hydrocarbons
Alkanes
Alkenes
Alkynes
• Hydrocarbons: organic compounds containing
only C and H
• Homologous series = group of compounds
with related structures & properties
– molecules have fixed, numerical relationship
among # of atoms
See table Q
3 Homologous Series of HC’s
Name of Series
General Formula
Ending
Alkanes
CnH2n+2
-ane
Alkenes
CnH2n
-ene
Alkynes
CnH2n-2
-yne
Which compound belongs to the
alkene series?
A.
B.
C.
D.
C2H2
C2H4
C6H6
C6H14
Correct answer = B
Alkenes follow the format CnH2n
A & C are CnHn , D is CnH2n+2
In which group could the
hydrocarbons all belong to the same
homologous series?
A.
B.
C.
D.
C2H2, C2H4, C2H6
C2H4, C3H4, C4H8
C2H4, C2H6, C3H6
C2H4, C3H6, C4H8
Correct answer = D
Members of homologous series all have same relationship
between atoms
Every compound in set D fits the formula CnH2n
Which of the following is a
saturated hydrocarbon?
A.
B.
C.
D.
Ethene
Ethyne
Propene
Propane
Correct answer = D
all alkanes are saturated