Hydrocarbons

Hydrocarbon and its features

• an organic compound consisting entirely of hydrogen and carbon

• generally colorless and hydrophobic

• faint odor

• 2 types on basis of carbon to carbon bonds

saturated hydrocarbons

• all carbon atoms are bonded through single covalent bond

• very stable and normally don’t react with common reagents

• called paraffins for their inactive nature

• also called alkanes

• general formula C_nH_2n+2

• burn with blue flame

• undergo subsitution reaction

Unsaturated hydrocarbons

• compounds made up of carbon and hydrogen in which any two carbon atoms are bonded through double or triple covalent bonds and other through single covalent bonds

• less stable than saturated hydrocarbons, they tend to react more readily with other substances. Examples include alkenes and alkynes.

• burn with sooty flame

• undergo addition reaction

Alkenes

• the compounds made up of carbon and hydrogen in which any two carbon atoms are linked through double covalent bond and rest through single covalent bond

• also called olefines

• general formula: C_nH_2n

Alkynes

• the compounds made up of carbon and hydrogen in which any two carbon atoms are linked through triple covalent bond and rest through single covalent bond

• also called acetylenes

• general formula: C_nH_2n-2

Homologous series

a group of organic compounds having similar structure and similar chemical properties in which the successive compounds differ by CH₂ groups.

members of the series are called homologues

characteristics of homologous series

• can be represented by the same general formula

• any two successive homologous differ by CH₂

• all members have similar buy graded chemical properties

• each member differs from the next member by 14 amu

• prepared by same general methods

Alkyl Radical

• the group of atoms resulting after the removal of one hydrogen atom from an alkane

• general formula is C_nH_2n+1

Functional group

• An atom or group of atoms which defines the structure of a particular family of organic compounds

• Hydroxyl (-OH) is alcohol

• Carboxylic acid (-COOH) is acid

IUPAC

• International Union of Pure and Applied Chemistry

• bringing uniformity in the nomenclature of organic and in organic compounds

• Parameters:

• number of carbon atoms present in one molecule of an organic compound

• kind of covalent bonds between carbon atoms

• numbering of carbon atoms in one molecule is taken from greek language

Uses of methane

• Methane is used for cooking food as gobar gas or biogas and as a fuel in industries.

• It is used to prepare carbon black which is used to make printing ink, shoe polish and paint.

• Methane is also used to prepare chloroform, carbon tetrachloride, methvl alcohol, formaldehvde, etc.

• It is also used in the industrial preparation of hydrogen gas

Ethane

• It produces heat on combustion so it is used in metal welding.

• It is also used to prepare carbonic compounds like ethvl chloride. nitro ethane, etc.

Propane

• It is a highly flammable gas so it is used as a fuel.

• It is used to make different types of carbonic compounds.

• It is used as a coolant in petroleum industries.

Butane

• It is used as a raw material for making synthetic rubber.

• It is mixed with methane in LPG (Liquefied Petroleum Gas) which is used as fuel. It easily changes to liquid on applying pressure.

Alcohol

• derived from alkane

• if one or more hydrogen atoms of alkane are replaced by hydroxyl group (-OH), the resulting compound is known as alchol

• Depending Upon number of -OH groups classified into:

• Monohydric alchol

• Dihydric alchol

• Trihydric alchol

Methyl alcohol

IUPAC name: methanol

• solvent for paints and varnishes

• prepare formules, paints, medicines and synthetic clothes

• used in dry cleaning

• used in manufacturing formaldehyde

Ethyl alcohol

IUPAC name: Ethanol

colorless and soluble in liquid. generally refered to as alcohol in daily life

1 Ethyl alcohol is used to prepare hard drinks like whisky, wine, beer, etc.

2. It is used to sterilize syringes and wounds in hospitals, health posts, and nursing homes.

3. It is used to preserve biological specimens in laboratories.

4. It is also used in thermometers.

5. It is used in the manufacture of polyethylene, terylene, soaps, paints, dyes, etc.

Glycol

• dihydric alcohol

• IUPAC name: ethane-1,2-diol

• no smell and is viscous, colorless and sett taste

• antifreeze

• used in manufacturing polyester

• used in air conditioning systems

• used in convective heat transfer

• used as dehydrating agent

• used to preserve biological specimins

Glycerol

• trihydric alchol

• colorness, viscous, hygroscopic liquid

• soluble in water and alcohol but insoluble in ether

• IUPAC name: propane-1,2,3-triol

• is used as a sweetening agent in food.

• used to make good quality soap, lotion, cosmetics, shaving creams, etc.

• used to keep the tobacco moist and it also prevents the dryness of fruits and foods as well as prevents them from decaying.

• used to protect skin by trapping moisture and prevent its drvness.