ORGANIC CHEMISTRY
Chemistry of compounds containing carbon.
Examples of organic compounds: Carbohydrates, fats, proteins, vitamins, enzymes, wool, oil,
plastics, petrol etc.
CARBON ELEMENT
Carbon bond with other carbon atoms to form, long chains and ring structures.
The chains can have 30 or more carbons e.g. polyethylene plastics
Carbon is the central atom in organic compounds.
Carbon has atomic number: 6
Carbon has 4 valence electrons
Forms 4 covalent bond
Types of carbon: Diamonds, Graphite, Coke, Coal, Charcoal, Carbon black
HYDROCARBONS
Hydrocarbons contain only water and carbon
Classes of hydrocarbons are:
Aliphatic-contain no benzene rings e.g. Alkanes that contain single bonds, Alkenes and
alkynes.
Aromatic- contain benzene rings.
Characteristics of hydrocarbons:
They are non-polar
Have low melting points and boiling points
The longer the chain, the more the boiling point
Insoluble in water
They dissolve in no-polar solvents e.g. ether
Aliphatic hydrocarbons are less dense than water, they float in water
ALKANES
A group of hydrocarbons that only have single bonds between the C atoms. This makes them
saturated hydrocarbons (each C bonded to its maximum of 4 other atoms).
Rules for naming branched-chain alkanes:
If H is removed from an alkane, the C and H portion that remains is called an alkyl group.
Alkyl groups do not exist on their own; they must be bonded to another group/chain.
Alkyl groups - described by using the prefix –yl.
CYCLYOALKANES
Cycloalkanes form when 2 H atoms are removed from the ends of an alkane, and those C atoms
bond to form a ring structure.
Example: methylcyclobutane
, If 2 or more substituents are attached to the cyclic alkane, the ring is numbered in the
direction that gives the lowest possible numbers to the side groups.
C-1 is assigned to the alkyl group that comes first alphabetically
Physical Property Type of Alkane
Gases C1-C4 unbranched
Liquid C5-C17 unbranched
Solids Greater than C18
Boiling point increase with the increasing number of carbons C6=68.7°C;
atoms
C5 with one branch = 60.3°C;
More Branching smaller molecule less intermolecular forces
C4 with 2 branches on different carbons= 58°C
keeping molecules together less BP
C4 with 2 branches on one C= 49.7°C
Alkanes and cycloalkanes are less dense than water
Alkanes and cycloalkanes are insoluble in water. Because they are
non-polar
ALKYL HALIDES
Addition of halogen (Cl, Br, F, I) to the hydrocarbon
It forms electronegative bonds since halogens are more electronegative than carbon
Uses
Solvents
Starting materials for synthesis of other compounds
Chemistry of compounds containing carbon.
Examples of organic compounds: Carbohydrates, fats, proteins, vitamins, enzymes, wool, oil,
plastics, petrol etc.
CARBON ELEMENT
Carbon bond with other carbon atoms to form, long chains and ring structures.
The chains can have 30 or more carbons e.g. polyethylene plastics
Carbon is the central atom in organic compounds.
Carbon has atomic number: 6
Carbon has 4 valence electrons
Forms 4 covalent bond
Types of carbon: Diamonds, Graphite, Coke, Coal, Charcoal, Carbon black
HYDROCARBONS
Hydrocarbons contain only water and carbon
Classes of hydrocarbons are:
Aliphatic-contain no benzene rings e.g. Alkanes that contain single bonds, Alkenes and
alkynes.
Aromatic- contain benzene rings.
Characteristics of hydrocarbons:
They are non-polar
Have low melting points and boiling points
The longer the chain, the more the boiling point
Insoluble in water
They dissolve in no-polar solvents e.g. ether
Aliphatic hydrocarbons are less dense than water, they float in water
ALKANES
A group of hydrocarbons that only have single bonds between the C atoms. This makes them
saturated hydrocarbons (each C bonded to its maximum of 4 other atoms).
Rules for naming branched-chain alkanes:
If H is removed from an alkane, the C and H portion that remains is called an alkyl group.
Alkyl groups do not exist on their own; they must be bonded to another group/chain.
Alkyl groups - described by using the prefix –yl.
CYCLYOALKANES
Cycloalkanes form when 2 H atoms are removed from the ends of an alkane, and those C atoms
bond to form a ring structure.
Example: methylcyclobutane
, If 2 or more substituents are attached to the cyclic alkane, the ring is numbered in the
direction that gives the lowest possible numbers to the side groups.
C-1 is assigned to the alkyl group that comes first alphabetically
Physical Property Type of Alkane
Gases C1-C4 unbranched
Liquid C5-C17 unbranched
Solids Greater than C18
Boiling point increase with the increasing number of carbons C6=68.7°C;
atoms
C5 with one branch = 60.3°C;
More Branching smaller molecule less intermolecular forces
C4 with 2 branches on different carbons= 58°C
keeping molecules together less BP
C4 with 2 branches on one C= 49.7°C
Alkanes and cycloalkanes are less dense than water
Alkanes and cycloalkanes are insoluble in water. Because they are
non-polar
ALKYL HALIDES
Addition of halogen (Cl, Br, F, I) to the hydrocarbon
It forms electronegative bonds since halogens are more electronegative than carbon
Uses
Solvents
Starting materials for synthesis of other compounds
