conchem

1. Uses of Alkanes Alkenes and Alkynes:
Uses of Alkanes:
The following are the uses of Alkanes-
Methane in form of natural gas is used for running scooters, cars, buses etc. L.P.G (a mixture of butane
and isobutane) is used as a fuel in homes as well as in industry.
Methane is used to make carbon black which is used in the manufacture of printing inks, paints and
automobile tyres.
Catalytic oxidation of alkanes gives alcohols, aldehydes and carboxylic acids.
Higher alkanes in form of gasoline, kerosene oil, diesel, lubricating oils and paraffin wax are widely used.
Methane is used for the manufacture of halogen-containing compounds such as CH2Cl2, CHCl3, CCl4
etc. are used as solvents both in laboratory and industry.
Uses of Alkenes:
The following are the uses of Alkenes-
Lower members of the family are used as fuels and illuminants.
Alkenes and substituted alkenes upon polymerization form a number of useful polymers such as
Polythene, PVC, Teflon, Orlon etc.
Ethene is employed for the preparation of ethyl alcohol and ethylene glycol (anti-freeze).
Ethylene is used for artificial ripening of green fruits.
Ethylene is also used in oxygen-ethylene flame for cutting and welding of metals.
Uses of Alkynes:
The following are the uses of Alkynes-
Acetylene and its derivatives are widely used in synthetic organic chemistry for the synthesis of cis- and
trans- alkenes, methyl ketones etc.
An oxyacetylene flame is used for cutting and welding of metals.
Acetylene is used as illuminant in hawker’s lamp and in lighthouses.
Acetylene is used for ripening of fruits and vegetables.

2. Acetylene is used for the manufacture of ethyl alcohol, acetaldehyde, acetic acid, vinyl plastics, synthetic
rubbers such as Buna N and Synthetic fibres such as Orlon.
Difference Between Aliphatic and Aromatic Hydrocarbons
Definition
Aliphatic Hydrocarbons: Aliphatic hydrocarbons are organic compounds composed of carbon and
hydrogen atoms, arranged in straight chains, branched or non-aromatic ring structures.
Aromatic Hydrocarbons: Aromatic hydrocarbons are organic compounds composed of carbon and
hydrogen atoms, arranged in ring structures with delocalized pi electrons.
Odor
Aliphatic Hydrocarbons: Aliphatic hydrocarbons do not have a pleasant odor.
Aromatic Hydrocarbons: Aromatic hydrocarbons have a pleasant odor.
Carbon-to-Hydrogen Ratio
Aliphatic Hydrocarbons: Carbon-to-hydrogen ratio of aliphatic hydrocarbons is high.
Aromatic Hydrocarbons: Carbon-to-hydrogen ratio of aromatic hydrocarbons is low.
Burning
Aliphatic Hydrocarbons: Aliphatic hydrocarbons burn with non-sooty flames.
Aromatic Hydrocarbons: Aromatic hydrocarbons burn with sooty flames.
Unsaturation
Aliphatic Hydrocarbons: Some aliphatic hydrocarbons are saturated whereas some are unsaturated.
Aromatic Hydrocarbons: All the aromatic hydrocarbons are unsaturated.

3. Delocalized Pi Electrons
Aliphatic Hydrocarbons: There are no delocalized pi electrons in aliphatic hydrocarbons.
Aromatic Hydrocarbons: There are delocalized pi electrons in aromatic hydrocarbons.

4. Difference between saturated and unsaturated hydrocarbons
The main difference between the two types of hydrocarbons is given by the fact that the saturated ones
contain covalent bonds between carbon atoms, while the unsaturated hydrocarbon has at least one
double or triple covalent bond in the main chain. This has some different characteristics.
Among the types of saturated hydrocarbons there are alkanes, while the unsaturated ones are alkenes,
alkynes and aromatic hydrocarbons. In terms of reactivity, saturated hydrocarbons are less reactive than
unsaturated ones and the combustion of the former generates a non-sooty blue flame, while
unsaturated hydrocarbons generate a yellow flame.
At the gas composition level, saturated hydrocarbons have a lower amount of carbon and a high amount
of hydrogen. The opposite occurs in unsaturated ones.
The origin is also different: saturated hydrocarbons are obtained from fossilized plant and animal
materials, unsaturated ones from plants.
In conclusion, the main difference between saturated and unsaturated hydrocarbons depends on the
type of bonds they contain. Saturated hydrocarbons contain only single covalent bonds while
unsaturated hydrocarbons contain at least one or more double or triple carbon-carbon bonds. Hence,
unsaturated hydrocarbons are more reactive than saturated hydrocarbons.