CAMBRIDGE
INTERNATIONAL AS
LEVEL CHEMISTRY
(9701) ORGANIC
CHEMISTRY NOTES
, CHAPTER 14: INTRODUCTION TO HYDROCARBONS
Carbon chemistry:
- Organic chemistry: the study about the properties and chemical reaction of organic compounds
- Carbon has been the main component of all living and non-living things
- Why do so many organic compounds exist?
o Carbon can form strong bonds with other atoms
o Carbon has the ability to form maximum of four covalent bonds with other atoms or by
itself due to its electronic configuration (1s 2 2s2 2p2)
Recap: orbital hybridization
Bond types and angles:
- Due to hybridization, carbon can form single bond, double bond and triple bond:
o Single bond
Sigma bond formed when the atoms bind and share one electron to each other
o Double bond
Pi bond formed through sideways p orbital overlap
Sigma bond formed through direct overlap hybridized orbitals
Single bond
o Triple bond
Forms when the atoms bind and share three electrons to each other
Overlaps with other same set of orbital to form two sigma covalent bond and
the 2py and 2pz overlaps to form two pi covalent bond
The molecule form through this bonding was also known to be an unsaturated
compound
,Representing organic molecules:
- Empirical formula
- Molecular formula
- Structural formula
- Displayed formula
- Stereochemical formula
- Skeletal formula
Empirical & Molecular formula:
Structural & Displayed formula:
Stereochemical formula:
- Shows the orientation of the bonding in 3D
o Wedge bond: out of the plane of paper (pointing towards you)
o Dashed bond: into the plane of paper (pointing away from you)
- Used to represent optical isomers
, Skeletal formula:
- Simplified version of displayed formula
- Only shows the functional groups without showing the symbols of carbon and oxygen
- Linear molecules
- Cyclic molecules
- Aromatic molecules
o Aromatic molecules e.g. benzene have a delocalized electron system
Naming Organic Compounds:
-
- Stem: number of carbon atoms in the longest carbon chain
o Add ‘cyclo-‘ if the carbon atoms are joined in a ring
- Stem-suffix: indicates the type of carbon-carbon bonds present in the compound
o Ethane: CH3-CH3
o Propene: CH3-CH=CH2
o Buta-1,3-diene: CH2=CH-CH=CH2
INTERNATIONAL AS
LEVEL CHEMISTRY
(9701) ORGANIC
CHEMISTRY NOTES
, CHAPTER 14: INTRODUCTION TO HYDROCARBONS
Carbon chemistry:
- Organic chemistry: the study about the properties and chemical reaction of organic compounds
- Carbon has been the main component of all living and non-living things
- Why do so many organic compounds exist?
o Carbon can form strong bonds with other atoms
o Carbon has the ability to form maximum of four covalent bonds with other atoms or by
itself due to its electronic configuration (1s 2 2s2 2p2)
Recap: orbital hybridization
Bond types and angles:
- Due to hybridization, carbon can form single bond, double bond and triple bond:
o Single bond
Sigma bond formed when the atoms bind and share one electron to each other
o Double bond
Pi bond formed through sideways p orbital overlap
Sigma bond formed through direct overlap hybridized orbitals
Single bond
o Triple bond
Forms when the atoms bind and share three electrons to each other
Overlaps with other same set of orbital to form two sigma covalent bond and
the 2py and 2pz overlaps to form two pi covalent bond
The molecule form through this bonding was also known to be an unsaturated
compound
,Representing organic molecules:
- Empirical formula
- Molecular formula
- Structural formula
- Displayed formula
- Stereochemical formula
- Skeletal formula
Empirical & Molecular formula:
Structural & Displayed formula:
Stereochemical formula:
- Shows the orientation of the bonding in 3D
o Wedge bond: out of the plane of paper (pointing towards you)
o Dashed bond: into the plane of paper (pointing away from you)
- Used to represent optical isomers
, Skeletal formula:
- Simplified version of displayed formula
- Only shows the functional groups without showing the symbols of carbon and oxygen
- Linear molecules
- Cyclic molecules
- Aromatic molecules
o Aromatic molecules e.g. benzene have a delocalized electron system
Naming Organic Compounds:
-
- Stem: number of carbon atoms in the longest carbon chain
o Add ‘cyclo-‘ if the carbon atoms are joined in a ring
- Stem-suffix: indicates the type of carbon-carbon bonds present in the compound
o Ethane: CH3-CH3
o Propene: CH3-CH=CH2
o Buta-1,3-diene: CH2=CH-CH=CH2
