Ethane

CHEMISTRY OF ETHANE
INTRODUCTION
– Molecular formula = C2H6
– Molecular mass = 30
– Empirical formula = CH3
– Empirical formula mass = 15
– State: Gas at room temperature.
– Occurrence: Ethane occurs along with methane in natural gas and gases from oil-wells. It is also present in coal gas in very small quantity.
ORBITAL STRUCTURE OF ETHANE
   Composition of ethane molecule:
   Ethane molecule consists of two carbon atoms and six H-atoms (C2H6 ).
   Nature of Hybridization:
   In ethane each C-atom is Sp3-hybridized containing four Sp3-hybrid orbitals. One s-orbital and three 
p-orbitals (px, py, pz) undergo Sp3-hybridization to produce four Sp3-hybrid orbitals for each carbon    atom.
   Sigma bond formation:
   Out of four Sp3-hybrid orbitals one Sp3-hybrid orbital of one C-atom overlaps with one s-orbital of
    H-atom to produce three sigma bonds and the last overlaps with one Sp3-orbital of other C-atom to produce a sigma bond between two C-atoms.
   Geometry of ethane:
   Ethane molecule is arranged in tetrahedral geometry in which central carbon atoms are surrounded by    H-atoms in three dimensions.

ethane_orbital

ethane

   Bond angles:
   HCH bond angle is 109.5o.
   Bond length:
   C-H bond length is 1.09Ao and C-C bond length is 1.54Ao.
METHODS OF PREPARATION
 FROM WURTZ REACTION
               2CH3I + 2Na irreversible_arrow C2H6 +2NaI
 FROM GRIGNARD’S REAGENT
   Ethane may be obtained by the hydrolysis of ethyl magnesium iodide.
               C2H5-Mg-I + HOH irreversible_arrow C2H6 + Mg-OH-I
 FROM ETHYL IODIDE
               C2H5-I + 2[H] irreversible_arrow C2H6 + HI
 BY THE CATALYTIC REDUCTION OF ETHYL IODIDE
               C2H5-I + Hirreversible_arrow C2H6 + HI
CHEMICAL PROPERTIES
 COMBUSTION REACTION
   Ethane burns in air or oxygen with a non-luminous flame to produce carbon dioxide and water. It is an    exothermic
               2C2H6 + 7Oirreversible_arrow 4CO2 + 6H2O + HEAT
 HALOGENATION
   Replacement of halogen with H-atom of an organic compound is called Halogenation. It is a    substitution reaction.
CHLORINATION:
            C2H6 + Clirreversible_arrow C2H5Cl  C2H4Cl2+ Cl-CH2-CH2-Cl
 PHYSICAL PROPERTIES
   It is colorless gas.
Its boiling point is -89oC.
It is sparingly soluble in water.