Describe two methods of preparaton of ethane. Given any three reaction of ethane.

Explanation

Mathods of preparation of ethane:
1. Decarboxylation: Ethane is preparec by heating sodium propionate with sodalime .
` underset( "Sodium propionate" ) ( C _(2) H _(5) COONa) + NaOH overset( Cao) underset( Delta) to underset("Ethane") ( C _(2) H _(6) ) + Na _(2) CO _(3)`
2. Kolbe.s electrolysis:
Ethane is obtained by the electrolysis of potassium acetate solution.

Chemical properties of ethane:
1. Halogenation:
Ethane reacts with chlorine in the presence of sunlight. Hydrogen atoms are substituted by halogen aoms successively. The final product is hexachloro ethane.
`C _(2) H _(6) + Cl _(2) overset( "Sun light")to C _(2)H_(5) Cl + HCl (or)`
`C _(2) H _(6) + 6 Cl _(2) overset("Sunlight")to C _(2) Cl _(6) + 6 H Cl`
2. Nitration :
Ethane reacts with nitric acid at `400^(@) C ` and gives nitro ethane.
`C _(2) H _(6) +HNO _(3) overset (400^(@)) underset( Delta ) to underset( "Nitreo ethane") ( C _(2) H _(5) NO _(2) + H _(2)O)`
3. Pyrolysis:
When ethane is heated in the absence of oxygen it decomposes giving ethylane and hydrogen.
`C _(2) H _(6) overset( 450^(@)) underset(Delta ) to H _(2) C = CH _(2) + H _(2)`